Depends on the brand! One of my businesses has a tiktok shop and it's the same things we sell on our own website and at events, but if the profile looks like a scammy one then presumably the shop could also be scammy. Use common sense I guess, if it looks too good to be true it's probably is.
Will say that tiktok sometimes offers random discounts or free shipping etc on items which the seller doesn't choose or have control over.