Looking at a bike need help

I have a friend with two bikes for sale a 97 750 ninja for $2000 or a gsx-r 75 with a big bore kit but it needs a radiator bracket and a new shift nob. it is only $1000 my question is which bike would be better becuase i dont know how much those parts are. I do know that the gsx-r blew away the ninja when he was riding it around.

What kind of condition are they in? The price your friend is selling them for is really cheap. Those would normally go for at least around 4k.

I would check up on the mechanical condition, and ask him questions about it. Check for everything. Check the condition of the wheels, sprockets, chain, etc. Look for leaks, and be aware of any type of smells when its running (smell of gas, oil, antifreeze). Take it for a ride and check out everything. Listen to the idle. Make sure its shifting good, and the clutch is working properly. Check the throttle throughout the powerband and make sure its not hesitating anywhere that would be abnormal. Check the feel of the brakes. Check the alignment. Rebound of the forks, etc. I know it sounds like a lot of things to do, but its your money and you need to make sure its going to be worth the investment.

I mean there could be a few minor things that are wrong with them that would still be worth buying, but make sure they aren't lemons. Good Luck!