97 cavalier for $250??

Hey guys. Theres a 97 cav around the corner from me that has some engine knocking, also teh interior is a little dirty, but thats not a problem. My friend went to go check it out, so i dont know how bad it is...My brother said its a possibily thats its the pistion skirts. What are some other possibilities it could be...i was just wondering, would it be a waste of time to fix up what ever is needed to be fixed and sell it for a profit? or not to bother with it??

if you can do the swap yourself you could probably throw a low mileage junkyard engine in for $750 and then clean it up and sell it for $2500-$3000