Now, I recognize this isn't a great price by any means. But maybe you're stuck with FreeSync monitors or something.
You can flash the Vega 64's BIOS to get performance very similar to the more expensive card. Since the card has dual BIOS, there's next to no risk doing this. Honestly if you're willing to do this, buying this at $20 above MSRP is much better than getting a Vega 64 at $500.