They’re around $10 from the manufacturer (for a minimum order of 50 pcs), so if you buy them for $2 you’re not getting a new chip. If you’re lucky, you’re getting a recycled chip from someone who claims it’s new because the guy they bought it from said so, but the chip still kind of works. If you’re unlucky, you get something else.
This whole video on “fake” chips is worth watching, but especially the bit between 2:30 and 5:00:
