ej92381

Hi all, im new to this site. Im thinking about purchasing a 75 rd 250 2moro. The bike is basically in mint shape. it has 9900 miles on it. Is this alot for a 250 2 stroke? also the guy saaid the bike will start and run, but under a load it bogs out and barely runs. he seems to think it is a crank seal. the price is $800. is this too much? also where would i find engine parts? where could i send the engine to be rebuilt? any help is appreciated. thanks