Happens on Ali Express all the time Martin. If you purchase something and go back to buy the same thing from the same seller 3 months later, the price will have possibly doubled. Things which cost me $2 a year ago now cost $10 0r $12. Not sure whether the sellers or Ali Express keep track of you somehow and spot you as a return sucker, but it strikes me as a bit odd at times. I have a times bought something, and the next day, thought "I need more", gone back to do another order and the price has changed already, (maybe 20c or so,-but in 1 day??) odd!
Not all sellers by any means, but enough to make you suspicious. Times I've paid for better shipping over free shipping, and the item's taken the same time to arrive, - even though it says less time?? The Ali Express std shipping is now all over the place, (from say $2.50 - $6) when it was all pretty much one price??
I have something which supposedly arrived in the country 27/10/20 (according to A/Ex delivery info. Then it apparently arrived in the country again about a week ago??? Still waiting and I bought it in October 13th. Now the date has gone back to 27th again. Mind you, our postal service is crap now as it's mostly done by private contractors who don't give a stuff. Found my jet unit for the boat lying in the garden a while back where a courier had tossed it over the gate,- it had been outside for 3 days till I found it by chance. I got an item once which took 2.5 months from China,- looked like it had been kicked round the world when I finally got it.
Still waiting for other stuff which was supposed to be here around the 12th-19th of Nov. No rhyme or reason to their tracking info, - totally irrelevant information,- you just have to wait and hope things will arrive. I don't see why, when we could fly to Shanghai in 12hrs, it takes more than a month for goods to arrive here,- especially when planes were arriving almost every day. (just had one from Hong Kong at mid day yesterday) It's only about 2hrs from Beijing to Hong Kong for eg. Their postal service seems chaotic with items sometimes going through 10 or more processes in a few days, then disappearing for a month or more before turning up in your box.
I'm starting to look more locally now for items like batteries, as I'm getting sick of waiting, and the shipping HK is charging now has stopped me buying anything from them. Rather pay the extra and have the items same day, (plus you have a shop you can go back to with a problem)
Don't forget that Ali Express is mostly CCP run now.
Banggood seems to have a better delivery method.