How much for a 318 Magnum?

I am selling the motor out of my 93 Ram to make room for a stroked 440. It's a good 318 Magnum TBI. I'm selling it along with many other parts to a guy here locally. Would $400 be a fair price on the motor? I'm selling basically everything with it wiring harness, accessories, blah blah. $400 for the lot of it or should I do like $500? I don't want to screw the guy but I would like to get a fair price. Just not sure on market value. Any help is great, thanks.