I regularly shop on AliExpress and have for years. I tend to buy items there that are identical to items I can find on ebay or amazon from local based distributors that would ship from within North America, but would also charge hefty amounts for shipping when the AE seller would ship for free, and without any additional import costs tacked on top of the shipping from the US. When I factored in the additional shipping and import costs, the price at AE was between 25-50% the price of the same item from a US based supplier with shipping and import, or from a Canadian supplier with shipping and taxes. I have never ever had to pay additional import/brokerage/taxes on any order from AE.
I probably have around 100 purchases by now on AE. Of the 100, I only ever had a problem with 3. Of the 3, one was the purchase of a chain brush. A few days after I ordered it, AE alerted me that the seller could not provide proof the item was shipped, and automatically cancelled the order and refunded me the total price. Of the other 2, one item was not as high quality as advertised in my opinion, and in the other, the item was scratched. For the item of low quality compared to advertised, seller offered a 50% refund, which I accepted. For the item that was scratched the seller resent an identical item without any scratches at no additional cost to me.
In my experience, I have had a far higher percentage of negative transactions with ebay purchases than AE.