I buy from AliExpress, OK?
Pretty-much constantly, because I'm always building something, and melting loads of solder doing it.
However, I only buy commodity-level electronic components and minor subassemblies, from which I do not require "guaranteed to the edge of the envelope performance". I also find myself frequently repairing a certain subset of delivered subassemblies; therefore, I buy in bulk whenever I can, so that I will have at least a few subassemblies that actually work when I receive them.
I also test EVERYTHING I receive on the day it is delivered. On components, the out-of-spec and failure rate is fairly high, and I report these numbers back to the sellers that I deal with.
If I need GUARANTEED, HIGH QUALITY, anything, I do not buy from AliExpress. I buy from North American suppliers.
In your case, there are several things that you should keep in mind:
- Listed famous brand name components, like Intel or AMD are quality control failed units that actually should not be on the market.
- Recognizable name brand subassemblies, like GigaByte, nVidia, EVGA, or MSI are likely counterfeit or "over badged" (marking a lower model number as a higher, and thus more desirable, model number); and, most--again--are quality control failed devices.
- Warranty is, for the most part, nonexistent.
- If a warranty exists, you will be responsible for the shipping costs of returning the item to China.
If you can deal with the possibility that you will be buying quality control rejects, or devices that will not work, or are outright counterfeits; as well as the possibility that you will have no warranty recourse for anything you buy, then go ahead that take the risk.
If, on the other hand, you cannot lose your money on such risky purchases, save your money until you can make purchases from your domestic retail suppliers.