GPLama tested 2 models from Thinkrider I believe, got good readings, worth checking out
here in Brazil the Thinkrider brand is pretty popular, cost-efficient trainers and the brand imports them with good value - about half what you'll pay for the similar trainer from more famous brands. What I hear about these trainers from online forums and such, is mostly good reviews too
So, I agree with Serge's point
If the Thinkriders are much less, like the example I mentioned here for Brazil, I'd go for them, should be a good option
But if the difference is not that substantial, then maybe should be more worth buying some local option, or looking at second hand offerings...
Oh, and don't forget to consider freight and possible taxes to the Aliexpress price.
worth mentioning, Shimano's issue is (from what I remember) that the readings oscillate a lot, and then are not trustworthy. GPLama also has years of reviews on Shimano PM's and comparison to other PM's
but if the readings are consistent, even if the watts are not exactly on point, then it should be ok. This comes from Hunter Allen, one of the pioneers of training with power. The real importance is not that you're doing 290, 300 or 310W during an interval, but the 100 or 150W difference from what you were doing prior. That's where the focus should be.