three:

1. A Durst A300 bought in 1975

2. a Saunders 4550 XL bought in 1994

3. an Omega Super Chronmega E 5x7 purchased in 2000 (moments before Kodak announced it was discontinuing 5x7 film for the first time (timing is everything )

nice to know I might be able to get 25 cents back on the dollar for my enlarger purchases!