In my experience, AliExpress is usually better than expected. Unless you go for the absolute cheapest the general quality is actually very high.

I bought some socks for example: for the price of cheap socks in a brick-and-mortar store I got some of the best socks I have ever owned.

I think AliExpress could do some really good bussiness if they were to add a QA person in the loop and would start selling 'premium' products under a different name. So far the median price/quality ratio of the things I bought has been very good (with a few duds, all gimicky electronic crap).