Here in the EU we have a sort of limit of EUR150, above which duties / VAT becomes more complicated. I sometimes split up orders in two smaller ones (with a few days in between) to avoid headaches.
The most extreme I did was with Aliexpress. I could order 4 items with "free shipping", but when I added a 5th item there was about EUR2 of shipping costs, which went up when adding more items. I wanted 20 of those things, so I ended up placing 5 orders of 4 items each consecutively. When the order arrived, all 20 items were in the same bag, but I did not pay additional shipping
Aliexpress is getting annoying lately. They are putting ever more falsehoods on their website. It is becoming common that you see ridiculously low "promotion" prices, and when you put it in your shopping basket and then login for the payment, the same product suddenly becomes much more expensive. Whenever I see this I cancel the order out of annoyance of them lying to me. Prices are already low enough that EUR 2 more or less does not matter and with such silly practices they are wasting my time. No way I am going to encourage that.