sorry, my bad- that should have been any form, not any technique...
I thought it was strange to make the offer in vt, but I assumed you had your reasons 
Never mind.
If I get it right, we get this
- I give up the three originals and the three copies.
- I get three tractatus Q12 in Cr+Co+Me.
- 105pvf of which
2a. keep 35p as 8p Corpus and 3p in each other form
2b. leave 70p to be invested with Guccio (in whatever forms he thinks are in great demand).
OK?
that works
Guccio would probably say "having a variety is important though Vim as less important as many buyers will pay in that as it's the easiest for most magi to acquire." So, considering Commission-free exchange, 70 = 5 * 14... so 5 in each form except Vim (45vf), leaving 25vf worth of vt... hrm, 5 Creo (10vf), 5 Rego (10vf), and 2 Intellego (4vf)... leaving 1 vf which I'll take in Corpus. so:
Creo 5
Intellego 2
Muto 0
Perdo 0
Rego 5
Animal 5
Aquam 5
Auram 5
Corpus 6
Herbam 5
Ignem 5
Imaginem 5
Mentem 5
Terram 5
Vim 0
These totals do not include Guccio's personal vis stash or what he has previously borrowed to exchange. I'll update his Vis Accounting.