I'm buying a 98 Chevy Prizm with 298000 miles should I be worried about the timing chain

You should be worried about the hole car. But if you are getting it at a cheap price, I would have it checked out. That is an interference engine and if something happens with the timing chain jumping, the motor would be done.

I hope the car is not more than $200.

Thank you for your feed back..i bought the car for 200

Thats good, now try not to put too much monies into it. But I would tear down to the timing chain to inspect it, do what it needs if your plans are to drive this thing. If that jumps time, then your done. Wouldn't be worth fixing.