The book rules in Covenants allow one to increase or decrease the "intrinsic" quality of a book by a handful of points depending on illumination, resonant materials etc. Do you take into account these modifiers when acquiring books with Build points? In other words, is the "same" book is priced differently depending on whether it is an Exemplar (-3 Quality) or a well scribed, bound and illuminated version inlaid with resonant materials (+1 Quality)?
Of course.
Price is based on Quality, not how that Quality came to be or how it can be improved at some later time.
If the time/energy is spent in-game to improve that Quality later, no problem!
So, for example, a generic Art text is bought with Build Points. It is then, in game, given the 2 easiest Resonances - it's now +2 Qualities higher.
If an Exemplar is bought, a Scribe can, using that as a template, turn out a text of +3 higher quality - that's exactly what an exemplar is for. But the original text is far less useful for study until that happens.
If any text is Glossed by another, that too raises Quality by another +1.
If a text is bought that already has the 2 basic resonances, is already glossed, and is not an exemplar - then those "improvements" are not available as a later option.
In each case, it's the original text that is being bought, not the potential improved version.
Of course, this makes it easier to game the covenant-building system (get a million exemplars and a scribe/bookbinder/illuminator, and books are way cheaper than just buying them straight). But the covenant-building system is so easy to game anyway (hint: stocks of vis, then trade) that it's best just to make an honorable agreement not to abuse it.
I usually modify build point pricing a bit based on the Q/L of books. High quality and/or level cost a bit more, low quality a bit less.
Aside from that, different book types gets different treatment.
Exactly. If one treats the rules as merely a "game" to be worked with sophist arguments to re-interpret to absurd ends (as some clearly enjoy), then there are endless abusive ploys possible.
But who can say with a straight face that they could realistically find 15 exemplars, one for each Art, much less one for each desired Ability as well?
If that's all you want, just take all your Covenant Points in Library and Vis and a couple Specialists, and leave the rest to game play.
I keep track of the source numbers for every book's quality - including the author's stats (and copyist's stats if necessary). This way, I know can know the resultant quality of any copy because while author stats wont change, physical makeup and the quality of the scribing and illumination may.
Well, this doesn't seem so strange to me, given that:
a) the exemplar is the "standard" format for a quick, easily transportable copy -- i.e. the kind of stuff a young magus would take with him when going to found a new covenant.
b) each Art has a basic summa (its root) that's very common.
There are 9 Roots of the Arts but I would never ever buy those with Build Points. If you meant Branches, there are 8 of those but they are too highly valued (IMO) to be made as exemplars. The normal 22 BP summae could be exemplar of vain summae.
EDIT: yeah, 31 BP is the normal cap but 22-ish looks good for exemplars.
'zactly.
(However, the key word there is "recognized" - ims there may be many books that fit the bill for the other Arts, just not one that outshines the rest.)
Branches (aka Pillars, the shining stars of the Arts) are, as described in Covenants, only given as gifts, and then only to those who are deemed worthy. There is no reason to assume they are ever "mass produced" - which is what an Exemplar is all about.
Roots (aka Foundations, the primers for most of the Arts) - that's far more possible. But even then, it would take a very "high fantasy" approach to the Order to believe there is so much demand to support the making of an exemplar in the first place.
Ez - take your logic to the next level. The fact that they can exist does not mean there is a (good) reason for them to exist, much less be available for purchase on-demand.
An exemplar is not made to be "a cheap buy" for Spring Covenants. It takes just as long to Scribe and bind and create, so it has a different purpose - and that is to be used in "mass production" (relatively so). It uses a little less parchment, takes up a little less space, is a little more portable, and probably has other traits that make it better for copying, and so is a perfect "model" for Scribes/copyists, craftsmen who are not studying from the text but merely producing more of the same, and again and again. And exemplars are made for that reason alone. So once a Scriptorium has one, there is no reason to make more, nor to sell that one.
(Thus there is no reason to expect an exemplar for anything but popular texts or texts to be used in mass education of some sort, etc. - and the few Spring Covenants in The Order are probably not enough to support that imo, not by canon math.*)
(* One Spring Covenant every few years iirc.)
So unless, in your saga, Autumn Covenants have produced "one exemplar for each Art" and then either go out of the Art Summae business or inexplicably make duplicates for no apparent reason ( 
) - they may exist, but they just aren't going to be available for purchase. (Damaged/worn out copies - maybe, and then only rarely. But that's a negative modifier on top of the -3 Exemplar.)
And if you believe someplace like Durenmar indeed engages in such a "production" approach to Arts Summae, then your Spring Covenant would have to be lucky enough to catch them when they are recycling all 15 old exemplars for new ones (and beat out any competition for same!) - and what are the odds of that? 
Hmm, you are right ... for some reason I was convinced every art had a root!
I definitely read Covenants differently from you. Exemplars are not "a little more portable" as you say, they are "extremely cheap to make, and very easy to transport, compared to full sized books". Everything in the text seem to imply that if you want to move a book to a distant place, you do not create a nice copy and move that -- you create an exemplar, move that, and make a nice copy at the destination. This also matches the way the system worked between scriptoria of monasteries in the middle ages. That's why it seems to me that young magi seeking to found a new covenant are more likely to have exemplars than full sized books with them.
That is an interesting concept. Redcaps are more capable than monks at moving bulky books but it might be cheaper that way.
Yes, it specifically says this. THe system isn't designed to restrain you from powergaming. You want to powergame? Go for it...it's not my job to stop you. Do what you like.
Exemplars aren't made for that reason alone: they are also made by craftsmen as samples of their skill, to show to potential clients.
Exemplars are meant to be models for scribes to copy, yes. They are a lot cheaper and more portable than a full book, but the two of you are both right, in that they are both for copying and for transporting to a great distance.
If you plan on gaming the system it tends to be easier to simply talk about the troupe that you want a more powerful covenant. We did in our present saga. We have a 75-ish vis income per year. Makes for a quite different saga than what we had in previous cases since vis is basically a commodity that allows us easy access to the hermetic product. Kind of living on an oil producing country, really. Not better or worse than a struggling covenant campaign. Our targets are simply bigger. Ars is not created for power equilibrium.
Cheers,
Xavi
If you're not a mage. What covnenant is challenged by the prospect of moving books?
We're not talking about a lone monk carrying everything on his back, or even on a donkey's back. Covenants have the resources to move more than just books with some reliability, so the relative "convenience" of having it "very easy to transport" is meaningless.
Yes, but why does one want to move that book a long ways? Just to then make one copy of it? Doubtful. The monasteries you refer to would have transported hymnals, psalms - but (probably?) not a Bible, because only 1 would be needed, and that would be a great work, not something to be treated as a commodity.
Covenants would operate on the same premise. Unless the transport is going to be extremely challenging, why commission a lesser copy just so you then have to make the one you actually want? Game formulae aside, it makes no sense to have to produce your own just so you can then have two, one that can't be studies from, unless (as I said before) multiple copied are going to be made.
But as said above - play the game however makes you happy.