My '96 GSX is almost 15 years old now, I bought it last September 2010 with 172 hours and it runs GREAT. It starts right up every time with out issue and has 150 PSI compression in each cylinder.
I paid $1050 for it, I figure I'll ride it till the engine blows (or looses compression) then ship it out to a engine rebuilder (Not SBT) and have the entire engine rebuilt from the ground up, that'll cost me about $1,000, so I'll have less then $2,500 into it (Spent about $400 to replace the LCD Info gauge, seat cover and add a boarding step) and should be able to see it's 20th birth day assuming uncle sam doesn't put a stop to operating a 2-stroke all together by then.
-TheChad