All the chinese stuff has come a long way, so cheap may be ok.

Always worth searching here

https://www.mig-welding.co.uk/forum/

I bought a 200A R-Tech machine over 10 years ago....probably a lot longer actually and it has served me well. Generally they always seem to get very good reviews, but their current version of mine is substantially dearer than your listings.

https://www.r-techwelding.co.uk/tig-...-ac-dc-200amp/

Who knows.....a good welder will never weld good with a bad machine, but a good machine might help a bad welder learn.

As a long term investment, I do believe it is worth buying good stuff. But that isnt to say the ones in the links may not be good, no doubt they do work fine. Most stuff originates in China anyway