I'd like to buy some used bike parts.
I don't want to shop online. I'm not very good at bike repair. I want to ask the seller if the part is the right shape and size to fit my bike. If they say "no", then I'll know not to waste my money and time buying it and trying to install it. If they say "yes", and it turns out not to fit, then I can get a refund without paying for return shipping.
I know that I can definitely buy used parts from a bike co-op. In fact, because co-ops disassemble so many bikes, they tend to have a better selection of used parts than most bricks-and-mortar vendors.
But I live in the suburbs. I'd rather not schlep downtown to get to a co-op.
There are two different individuals in my neighborhood who fix bikes in their backyards and sell them out in front of their homes. Perhaps they'll have the parts I need. But perhaps not.
Another possible alternative for me would be to go to a local bike shop.
What's the general rule? Do bike shops that sell used bicycles normally also sell used parts?