A number of factors.
- RX570 is an older product. AMD has cut prices over time with new product releases.
- The GTX1050 is a discontinued product due to the GTX1650, so low stock is driving higher prices.
- RX570 is more power hungry and requires at least a decent 450w unit. GTX1050 doesn't need a good PSU.
- The RX570 doesn't have an Nvidia badge. As bad as it sounds, especially on the used market AMD cards go for less money than comparable Nvidia cards.
A while back I sold my GTX1050 2gb for $75 an purchased an RX480 8gb for $89, which i subsequently overclocked to RX580 performance.
Not really any strings attached. Higher power consumption and a little noise, but 4 times the vram and double the performance is certainly...