And they'll keep doing it because people are buying them - 31 sets sold on my link alone.
FWIW I needed new injectors for my '99 (one got flaky when it was warm), and I certainly weeded out the obvious scams on eBay (like the above) and ended up buying a set for $250-ish. I really thought they were going to be genuine. Got them in, and despite them being pictured in the auction with Toyota parts boxes (like the above), they were just in generic plastic baggies. I figured I'd give them a go, since at that point my truck was apart, and it's not a trivial task to get down to the injectors on a 5VZ. And... they sucked. A noticeably uneven idle (a good clue that the volumes are not well matched). And hard cranking, warm or cold, a clue that they're leaking down when shut off. I quizzed the seller and they said:
- they 'buy in bulk' - that's why there are no parts boxes (lol)
- I should put at least 100 miles on them to 'break them in' (super groaning WTF-lol)
I put 100 miles on them, they got worse, not better, so I demanded a return. And they agreed without an argument, sent them back and got a 100% full refund. And I went to a junkyard and got a set of actual OEM injectors from a wrecked 3rd gen. And they work perfectly.
Oh, and another eBay gem. I needed to do a TB/WP, so I looked on eBay for complete kits. And found one pretty damn cheap. 'Genuine OEM' it said. So like a gullible idiot I ordered it. And when it came in a big box, I opened it and found a bunch of smaller plain white 'generic' boxes that said, literally, 'OEM' on them. As in, the 'brand name' was OEM. And it was all obviously cheap knockoff crap. I got a full refund on that one as well (and bought an actual genuine kit from aircabinman). But I still find that amusing, 'OEM brand'!!!, literally. But not figuratively.