2.5 and 3 gal kegs weren't used for 20 years by the soda pop industry...so they only really exist as 'new' or 'like new' from homebrewers that bought one new.
the used 5 gals are getting scarce so even they aren't cheap like in the past (you used to be able to get 4 cornies, shipped, for $100)
Primary: English Mild
On tap: Pale Ale, Lancelot's Wheat, English Brown Ale, Steam Beer, HoovNuts IPA
Bottled: MOAM, Braggot, Raspberry Melomel, Merlot, Apfelwein, Pyment, Sweet mead, Cabernet
Gal in 2009: 27, Gal in 2010: 34, Gal in 2011: 13, Gal in 2012: 10