>8595219Seeing as the set in question was originally $20, it wouldn't have been too unreasonable for someone to buy multiple copies of it. (Especially as it was the only set with a Sinestro minifig available for a few years.)
Did Bricks & Pieces exist back in 2015? It might explain the sheer quantity of the piece the sellers have avaliable.
>>8595273Never underestimate bootleggers: they love anything they can make into a lightsaber. (Although after checking AliExpress, I couldn't find any trans-yellow ones; just trans-neon green.)
It would hard to tell with the piece itself. Issues with transparency/color maybe? Of course, using skepticism when buying the piece helps too. (If the amount of parts sounds too good to be true...)