So, I've been quietly adding to my equipment collection for blockchain mining, including bona fide ASICs and related power supply units and so on. Since I'm just getting started, I'm not interested in dropping big dollars on a stupid adventure, especially on chains that are already well-developed with low chances of block success. I'd rather tinker with discounted used equipment, maybe lose a few dollars on the way, and possibly learn and gain a lot more. Unfortunately, with any used market, the risk increases for ending up with bunk equipment or getting ripped off.

So far, I've got three working Bitmain power supply units and one confirmed working ASIC. And, unfortunately, I've been landed with one non-working ASIC as well which now becomes a chunk of parts for salvaging. Everything I have was bought through low cost sales on eBay, which follows my plan, but the bunk ASIC did cost me something like $40. It's annoying to get ripped off with crap on a bad sale, but that used market risk is how you score good deals. I'll still take chances, but there are some rules I should have followed and didn't.

My piece of junk ASIC

First, fully check the ad details and condition descriptions. If the eBay ad says AS-IS or NO RETURNS, that's definitely the first red flag. Good sellers will honor refunds or returns for bad sales. I would know, I have a feedback rating of over 1,400 that's been in place since the late 90s. I've only kept it by honoring my sales and customers. 

Second, a low feedback rating generally means little activity or a very new account. Most rip-off characters create new accounts repeatedly, purging off bad feedback and selling more scams with a new account changed as often as one takes a shower or changes their socks. 

Third, never spend more than you're willing to lose. In my case I did get something, so now I just need to figure out how to make the most of it. But, in the worst of situations, you make see your money simply disappear and get nothing. So, never drop what you can't afford to be without. In a lot of ways, buying used online can be like gambling; it's exciting when you get a win, but eventually you also lose.

As for my ASIC project, I'll continue to keep adding equipment. Getting a good ASIC system of 3 or 4 machines for 25 percent the cost of one brand new one is still worth the effort, especially if they start producing consistently when I get things running. And it is fun to go through the ups and downs of a build adventure. It's far more interesting than just sitting at a computer waiting for crypto handouts or playing day-trading in a rigged whale market.