I just paid 1500$ for a blown engine 350 diesel 4x4. I also saw a v10 engine recently for sale for 1800$. I almost jumped on it to convert oil to gas, but decided to stick with the smoked mistress.

 

KBB Fair private party for an XLT list at just under $12k. From the numbers being tossed around here, it would have to be really really really cheap to be worth the risk. You'll probably be better off finding one that's running and in need of minor repairs that you can do yourself to save some money.