Yeah I saw the hisense as well. I'm just nervous about these brands like you said lasting.
What's the benefit of going with Costco? It looks like best buy offers a better deal.
Return policy and Costco usually extends (and stands by) their warranty better than anyone. Other big ticket local retailers aren't bad (ie best buy) but nobody will give piece of mind like Costco. Like 2 years ago I dropped like 2 grand on the TV they're talking about above from Costco. Had issues after 3 months, and they came to my house and picked up for free, gave me zero issues and a full refund.
That said I also almost went and bought the TCL 6 series (which was a best buy exclusive) and they aren't the best when it comes to returns/warranties.
At the end of the day I'd go with the best price regardless of retailer, but if price/logistics work out Costco is well known as the best place to buy a TV