I have a bunch of computer towers. I am selling them mainly for the cases and power supplies. The motherboards and graphics cards work but are old. The hard drives work but most probably need an OS. Ram could be upgraded. You could get away with restoring a PC with the parts inside, but what I would do if I had time is donate or recycle the parts except the power supply and case, then build a custom PC.
$30-$50 each
I also have keyboards and monitors for sale, as well as a whole bunch of other computer stuff. Need to make lots of room.
Car stereos and internet devices are $5 to $30 for used. New stereos are 60,70, & 100