Why the hell are important books like RoP: Magic and RoP: Faerie out of print and so hard to find??? I have found only a couple copies of both around the internet and they range from 490 to 520 dollars for RoP: magic and 121 for RoP: Faerie. Not to mention books like Hermetic Projects which I've seen being sold for around fifteen hundred dollars. I am aware that I can get PDFs but I would like to complete my collection on my shelf. Having a binder with loose sheets in cover pages or a PDF on my computer just isn't the same.
That’s nuts. For 1500 I’ll sell you a few of mine. 
Print the PDF.
Tremere house bought them all and have them locked up in Coeris for security reasons.
Have you tried the local public library? Some are getting into book printing at reasonable prices. I don't know what their rules would be on a single copy of a purchased PDF of an AM supplement would be, but there are books available to print from archives for a content or copyright fee.
If the AM line isn't available like this, maybe it could be?
I had RoPM and RoPI printed at my local print store and basic binding. Cost me about $20, but its nice to hardcopy.
Wow. That's expensive.
Switch to PDF. Just switch to PDF.
But getting it printed at a print shop doesn't count for having a collection on your shelf.
The RoP:M and F books are both pretty unbearably heavy on PDF, almost unusable on a phone and actually take a few seconds to load on my desk top.
Have you lookied at a bookbinder? I have a friend who runs one and they will put a proffesional cover on any book for $40 or so.
No one is actually able to sell them for those prices though. They're mostly automated pricing models on Amazon or wherever.
If you want originals, keep an eye on ebay, amazon, abebooks, rpg.net, rpggeek marketplace, rpg dealers like nobleknight or waynesbooks or many others. You'll find them eventually. You may pay out of print prices, so above original retail price, but nothing like the prices you listed.
These books were printed a long time ago, and actually, sold really well to Ars Magica fans... hence them being out of print and hard to find. 5E is officially discontinued, so everything you see for sale is old stock.
I wonder if a kick starter campaign to reprint the out of print books could be an option (not so subtle nudge). A kick starter would allow Atlas to do a smaller print run. I know I’d Pay premium for hard copies of some of the books I only have in pdf.
I'd think it easier to convince Atlas to support print-on-demand for books they no longer stock than new printing of old books via crowdfunding. POD isn't the most economical option for the buyer, or the most profitable for the vendor, but it does save the producer from having to worry about unsold copies, warehousing, fulfillment, or going out of stock. And it would still be cheaper than the "collector" prices asked for out of print titles on eBay or NobleKnight, if the books can even be found in good condition. Nothing about the Ars Magica books should prove too challenging for the POD vendors, they're of a common size, reasonable page count, with black and white interior printing. None of the problems of some massive World of Darkness tome from Onyx Path that has to be split into 2 volumes, ugly ink costs for full color art, or the weird size of the otherwise gorgeous Nobilis 2nd ed. - the only problem to be addressed would be the page borders that run right up to the page edge. And Atlas already sells through DriveThruRPG, though not currently Ars 5th, so it's not even a new business to deal with.
If they ever publish a new "the edition is complete, here's an indexed compilation of all the various guidelines and rules that have been spread across the various books, with errata" volume, then a Kickstarter might be the way to go. But for books that have gone out of stock, I think the demand is too small and unpredictable for anything other than print on demand.
Never participated in a kickstarter campaign then?
X gets you A
X+Y gets you A and a limited edition nick nack B
2X Gets limited edition A with a different cover, and a signed B
3X gets limited edition signed A, B, and a thank you in A
Etc etc. it's just a daydream anyway, why dump on it?
I'm rich, I'm rich. I'm rich: I'm going to take a book bath tonight. 30 books in the tub (no water): That's 15.000 dollars to relax in. Muwahahahaha!
And one day I'll burn them. They are worth more than our two cars combined. What a gesture (a shame that books burn so lousily).
[Door bell rings. Two strong men in white ente. What do they want with the strait jac