What kind of engine? If it's a small block V-8, it's probably junk because there are so many of them available. A full-pressure 235 might be worth saving if the block isn't cracked or some other major disaster is present. The most common cause of a locked-up engine is piston rings rusted to the cylinder walls or a spun rod or main bearing. All those things are repairable, just expensive. An engine rebuilder might give you a few bucks for the engine as a "rebuildable core".
Jerry

"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!
There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway
Love your enemies and drive 'em nuts!