Wow, that is indeed an incredibly >>cheap<< price. I've MIG welded for years, and have a pretty good TIG setup (however I'm NOT a good TIG welder). You likely know the benefits of TIG - but here are the issues that I have with TIG. It uses lots of pieces and parts in the torch (eg $$), requires dexterity to feed a separate wire filler while at the same time regulating the heat input with a separate controller and keeping the TIG rod from contacting the base metal (which then requires resharpening). Plus a TIG machine should have controls that set: gas preflow, ramp rate, pulse duration, post flow, etc. which can be tricky to figure out. TIG is much more complicated to own and operate than MIG. TIG is all about "hood time", it takes a lot of practice. However, a good TIG welder will prefer TIG over MIG, particularly if weld penetration is critical.
In general I find TIG welding much like patting your head and rubbing your stomach at the same time. But, when the stars all align, it sure makes a nice weld. I use it mostly on delicate parts where I need careful heat control and precise weld location. I've also found it useful for brazing.
I highly recomment watching Jody Collier, Welding Tips and Tricks,
https://www.weldingtipsandtricks.ht...icks.com/tig-welding.htmlcom/tig-welding.html There are a bunch of YT welding videos, but Jody's are the best - in my opinioin he sets the gold standard for welding information on the internet.
Regarding Argon - it's expensive, I'd recommend renting your tank, getting a small one, and then decide whether to increase the capacity based on how much you use it. Also, you can more efficiently control gas usage by installing a Flow Meter, rather than guessing the flow with a typical regulator pressure gauge.
https://www.amazon.com/BETOOLL-HW9003-Argon-Regulator-Welding/dp/B01I67VKFW