Rm250

I'm looking to buy a 1998 RM250 this week. It looks like a good deal; Pro Circuit pipe and silencer, Pro Circuit ported cylinder, and Renthal bars. The bike is in good condition and has good tread on tires. The is $500 under the kelly blue book and I was wondering if these bikes are prone to any problems that aren't obvious. Any help or knowledge would be greatly appreciated. Thanks.

Blake