Luger Question

I usually notice a fair amount of lugers at gun shows, and lately have taken a fancy to maybe buying one. I would want a shooter- not a collector's piece, so I don't care if it has been reblued or import marked. I do care if it doesn't have matching numbers on the major parts, is rusty beyond a few specks here and there, or has a bad bore. What is a reasonable price, and are there any special things I should look out for?