Thanks for this. Just called and ordered a 5600x for $365 shipped! They have 5600x and 5800x available (Others you have to buy with combos, full system)It's kind of nebulous as different states treat taxation differently... see https://www.thebalance.com/which-sales-tax-rate-do-i-charge-my-customers-3193251 for example.
JNCS could very well be rolling up the sales tax into their published marked up price, as they would be responsible for collecting/paying the sales taxes ultimately. I don't know.
Their website looks like ass but I did some digging into their other web presence to determine it was a legit business before placing my order. They are a small boutique builder, and their full system builds seem to be priced accordingly (ie.. overpriced - I'm surprised they are even willing to sell the cards by themselves instead of putting them in systems for an even larger markup... but I guess demand for cards far outstrips the demand for full builds)
I expect their cards are coming directly from manufacturers or distributors as they receive cards in batches and publish expected dates (currently the only thing showing is 8x EVGA 3090 FTW3 Ultra, but at the time I bought mine they had two batches of 3080s being received a week apart).
I'm not trying to endorse them, just relaying what my experience was.