A lot of ALIexpress sellers are chancers who place speculative listings, and then try to obtain items if they get an order, and if they can't, then cancel the order, and though you get a refund a couple of weeks later, you can lose out if the exchange rate has changed in the meantime.
Or they ship something totally different, and you then have to try to get redress through Aliexpress's dispute resolution, which IME is a joke - 7 weeks to be promised a partial refund after the seller admitted they'd sent the wrong item, claimed it was equivalent (despite them still listing both the ordered and shipped items) and admitting they won't sell the correct item in 1-offs. And also out of pocket from import duty on higher cost item.
Always read actual seller feedback (ignore percentages etc. - these are misleading), and steer clear of any that have no or bad feedback