I bought a mixed box of tools at a garage sale Saturday. There were a few Snap-on combination wrenches, but no where near a complete set. Non-ratcheting, around 12-15mm. Good condition, what would each one be worth? I have the sizes covered in craftsman, gearwrench, and kobalt. Trying to decide if I want to add to and make a full SO set, or just sell them and get some of my money back- either way, not sure what to expect money wise.