I've bought computer stuff from Ali Express. It's slightly similar to Amazon and others sites which just let people throw up store fronts. Of course it's the overseas version so most stuff you are the importer of record and it's your responsibility to pay any duty and such. Which is part of the reason some of the stuff is much cheaper than the same item purchased here. Importers bringing it in for resale have some fees they have to pay that the prices don't reflect.
Much of it you won't have fees or tariffs because of the small amount you are buying and certain stuff is completely exempt. But there are some gotcha's. I have noticed recently some items say they ship from the US, so in that case, there won't be any import fees because whomever brought that stuff here is responsible. Assuming you are in the US of course.
Let us know how they do.