how much can i get for a 2000 infinit qx4 that needs a motor

Less than a $1000 even if the rest of it is in really nice shape.

What's the min and max?

That is up to you. Without a lot of information and photos I could only throw a WAG at it. If you have the time, start out high and reduce the price until you unload it.

I don't have any pictures. My mechanic has it and he said $500 and I think that is low because all he's going to do is get a motor and resale for much more. That's why I was asking the min and max so I can tell him.

If you want more you could pay him to install a used engine. Do the math and see if you would make any money on the deal.

$1800 for him to install a motor