I buy cell phones for $1 each. I get alot of 3g and 4g smart phones coming in now. The go for about $10 each for parts. The ones i have tested and gotten to work/partially work they go $20-$50 each. GPS can be the same way if the screen is not broken all they usually need is the internal battery replaced, then you can turn around and get the full used price for them. That is if you like to fiddle with electronics.