The general consensus seems to be hit and miss. If it looks too good to be true, it probably is. The issue with Ali is that half the sellers use the same photo for different items. I think that it’s not worth the troubleshooting effort if they end up being fake.
That said, products such as Arduino clones, Adafruit module clones and the like can be had very cheaply if you are willing to wait a month or 3.
Tayda is mostly cheap and in my experience, very reliable. The cheap shipping takes 3-4 weeks to the UK from Thailand, but I think they have a warehouse in Colorado so it might be a good deal faster in the States.
There’s also some good regional ideas in that thread.
