Not only that, but just because you get a 1099 doesn't mean you actually owe taxes. You only owe taxes if you make a consistent profit on those sales and you are only taxed on the gains. I don't know too many non-commercial sellers that are profiting on used gear...
You sell a guitar on Reverb, you aren't exactly profiting. Depreciation, selling fees, PayPal fees, shipping fees, your time and effort to maintain the gear, what you put into the gear for upkeep (strings if a guitar, tubes and such for an amp, etc.). All of that comes out of the profit you might make.
I sold a car a few years ago for a huge profit. Way more than $20K. And I didn't owe any tax on that.
