Has nothing to do with price fixing. Altcoin mining has roared this year, especially Ethereum, and people are buying anywhere from 3 to 300 GPUs at a time to mine with. That leads to massive shortages.
I watched a thing yesterday about a dude with 192 GPUs in his shed mining. The next video was about someone who bought over 20,000 GPUs to mine with.
I shop on the used market and don't spent more than 220 on an RX 480 8G or RX 580 8G. No _good_ prices on nVidia stuff yet; they're just too high quality and high performing for there to be a price drop even on the used market.