I built my own table, and although it is oval (not round), I'll give you my two cents.
My table is 92" x 48" yielding a circumference of 234". I can fit 10 comfortably. I can squeeze in 11. 12 is up close and personal. A 72" round table has a circumference of 226" vs. 188" for a 60" table. The general rule of thumb (I believe) is 22 to 24" per person. It sounds like a 72" table would be the way to go (if you have the room for it).
Materials for my table cost about $225. That includes 2 sheets of plywood, folding legs, black vinyl rail, high density foam (rail), blue felt, headliner (table), 10 plastic cupholders and rope lighting. If I was going to sell tables as a profession, I'd probably start pricing them at about $500. I don't know if I'd pay more than that for the table that you want (unless it had pedestal legs). $400 - $500 seems reasonable.
I am selling mine now, but I am only looking to get 2 X materials because I want to build 2 new tables. My home game is growing. This is what my table looks like:
http://cgi.ebay.com/ws/eBayISAPI.dll...192734034&rd=1
Big thumbs up of the sunken in cupholders. I've been hosting games for over a year on my table and have had ZERO spilled drinks. I'll never build another table that doesn't have sunken cupholders. I'm thinking about upgrading to brass cupholders next time.
Stablity. My table is very sturdy with the folding legs. I don't know how sturdy a round table would be with just 2 sets of folding legs. I'd want 3 or 4, or at a minimum, I'd like to see his finished product before I buy. Lean on the table. Knock it around a little bit. If it seem sturdy, buy it.
I hope this helps. Good luck and enjoy the table!