Buying Used Equipment on the Internet

The vast majority of 100% feedback, hobbyist gear traders on here are not going to stick you with a "lemon". I once sold a DAC that arrived DOA -- somehow it went bad between my last listen and arriving at the buyer. After a couple hundred transactions, something like this is bound to happen.

After a friendly & brief exchange of diagnostics (did you try power cycling etc) I took it back with no aggravation, and issued a full refund plus return shipping costs and an earnest apology for the trouble.

Of course your experience can vary greatly by seller. That’s the risk component. That’s also why these prices are a lot lower than retail. If you’re not comfortable with that, if you’re going to obsess over some obscure blemish on the bottom of a chassis (PLENTY of items arrive new from factory with blemishes, btw), or want to return items after trial because they’re not your preferred "flavor", then you need to pay the premium to a dealer (dealers will also have limited tolerance for that too lol).

I bought and sold a several components on usaudiomart. It's about communication, you pretty much have to figure out if the person on the other end is trustworthy. Ask some questions that aren't realistic but the responses will be telling:

"I will be in the area, can I listen to it?"

If the response is: "it's in the shed, I just had surgery, I can't get up, well.... why would his/her priority be to sell this thing."

As a seller, I can be picky too. I don't want tire kickers in my home, and will generally ignore such buyers, unless I know you. If you don't trust a seller's feedback history, why even bother?

Even if you try this on a 0-feedback seller that has intent to defraud, they might just call your bluff. They can cut contact any time and what do they have to lose?