AliExpress and other small online shops does not have stock.
- The end customer place an online order to a small shop.
- After the payment was approved, the small shop place a centralized order to the warehouse.
At this point it is very clear that the warehouse changed the price, so the price jumped about 5-10 times over night. A small shop will not have money to take the hit, so they will try to mitigate the loss. No matter what, the shop will take some damage, either in money or in reputation.
Insisting to get the order is a very unfair thing to do to the shop owners. Most of those who ordered placed their order not because they were actively looking for a calibrator, but because knowing/hoping they'll get some undeserved advantage.
Legal? Yes.
Ethical? No.