The link for the $500 gaming PC, looks like you save around $150 before tax.
I can't seem to find this model number on the first page of a Google search, so I'm assuming it's a special model specifically for BF and/or Walmart. You can see evidence of them being cheap in the pictures; there's only one type-C and one USB 3.0 port in the front. I'm assuming there's two more - hopefully three - USB ports in the back. It also utilizes a combination headphone/microphone jack instead of two separate ones. The GTX 1060 is the 3 GB version, the stronger variations seem to have 6 GB.
You're still getting a lot of bang for your buck with a core i5 and GTX 1060 in general though.
The 3GB 1060 might be an issue for some, though still probably can't beat this price - or really even get close to it with an NVIDIA card. Beggars can't be choosers basically, and as this is about the max I'd consider throwing at any computer at this point, I"m definitely a "beggar". Right now I don't see anything close to similar for less than $700 or $800. That HP Omen that's been on sale at Best Buy a few times I don't believe has breached $700 (currently $819) - and though it's probably a better machine overall it also uses the 3GB 1060. I've been tempted by that one, but I haven't had a desktop PC in like 15+ years so it's tough for me to commit unless the price is just rediculous and it can do legit gaming. $499 gets me close to ridiculous.
Unless there is some fatal flaw, like the system uses a weak PSU that will blow up on you, $499 seems like a great price. I"m definitely considering going for this. I would assume the 3GB GPU could be upgraded in a few years, and maybe the next gen model (or 2 gens out) of the same card starts at 6GB instead of 3GB while drawing similar power.
Being a desktop, I would assume there'd be no issues with soldered RAM or anything like that?