What is this truck worth? 1981 F-150 Ranger, 8ft box, V8 180k miles. (See link below)

It is sold as-is and I don't have a trusted mechanic, so any advice on how to have it checked out? (I am no mechanic!)

Cars For Sale: Car Details - AutoTrader.com

Also, I'm not clear why it's called both F150 and Ranger?!