Hello, Japanese Th66 user here. You mean this, right?
I can't say for sure it's perfectly safe, but I bought my TH66 from here. I haven't had any problems. Now with the depreciation of the yen, I think it's a good time to buy. Enjoy your TH80!
Is it really cheap on Aliexpress?
Not sure where you're located, but I'm based in California and I see a deal on Amazon on the SK68 for $44 USD. Also, unsure of the warranty, but Amazon has pretty flexible returns.
https://www.amazon.com/gp/product/B08GG7B977/ref=ppx_yo_dt_b_asin_title_o00_s00?ie=UTF8&th=1
I hope this helps you!
https://www.amazon.com/gp/product/B087QTR4CT/ref=ppx_yo_dt_b_asin_title_o09_s00?ie=UTF8&psc=1
The right shift, and the right alt,fn,menu keys are of different size. Everything else is fine