I would ask to buy 35 feet and shoot and get it developed. If it's good enough then buy. Chances are good though that it'll probably be really washed out.
Are you a student? You can get 400ft of 7285 Color Reversal from Kodak for $99.34. I would go that route.
also from what i have heard when shooting with old film like that it is a good idea to rate your ISO lower than what it says on the can 100 ASA -> to 50
I have some old 16mm color outdated film a couple of years old that I want to sell. If interested let me know... also have 16mm film equipment. (Canon scoopic, and Bolex outfit complete.. also Bell & Howel 70DR w/ 3 Angeniux lenses...