Something similar is happening here in Germany and presumably throughout Europe. To circumvent price regulation for offers, prices rise 30 days before promotional days.

It is especially bad with delivery services: restaurants double their offer prices, only to then advertise them with a 50% discount.

It's like Harbor Freight, where if what you want isn't on sale now, wait a week or two and it will be.

Also, it's not a great place to get a good price on items where demand outstrips supply, like SBCs and mini PCs. You're better off getting them directly from the supplier or through their distributors.

I suspect you need to use the '20% off' (what they call it) coupon to get a properly discounted price. These aren't unlimited but operate from a fixed pool which gets topped up at midnight and more on certain dates, so if you try one day and it fails, will often work the next day.

I know as I operate a youtube channel and website (cheerful.cheap) and each 11.11 they send me a bunch of coupons.

I run a site which scrapes MiniPC prices from several stores every day. I was excited for the AliExpress 11.11 sale (their version of black friday) thinking there would be good deals to scoop up, or at least show on my site. But while they make it look like an impressive sale, stores just quietly delisted, relisted, renamed, and up prices over the last week or two. Quite a trick! Luckily since I normalize all entries into their composing specs (CPU, RAM, Disk, etc) it's much easier to track despite these tricks.