I should start a newsletter for book auctions and prices. I'm no expert, but I have been following the prices of Greek and Latin textbooks for over 3 years now....
anyway, here's what looks to be a book in good condition: Plato's Apology. The books on Textkit, and it's great.
http://cgi.ebay.com/ws/eBayISAPI.dll?Vi ... gory=11098
Don't get carried away with bidding, it comes up for auction all the time. The only question is what do you want to pay for a copy in good condition. Most the time they're ex-libre or they are marked throughout.
This book's described as very good - but there are pencil marks. How much is a question for the buyer. I would pay maybe $10 to $12 US and up to $20 for a book in good condition with no markings.