The domain businesscards.net, which was first registered in 1999, sold for £7,931 ($13,100 USD) yesterday– a fairly decent price in my opinion.
Other notable sales:
attending.com- $10,000
sushifan.com- $5,000
lesbianpornvideos.com- $3,500
ebook.pro- $3,900
ginv.com- $3,800
The sale price of attending.com is surprising high. I think gerunds are awkward in a domain. Ebook.pro and sushifan.com both faired well at auction, too.