I would not say that I, personally, found mig easier.
I, sadly, had a lot of experience with electronics construction, and, with a soldering iron, the heat source and the filler are independent. I was very used to this concept.
Tig is the same. Mig, on the other hand, is all connected. Your wire feed, amps, movement across the material must all be correctly related. For me this was harder.
Id probably still tig everything if it was quicker, and evreything was clean. I mean I've even tigged bits of landrover before....
Tig isn't that expensive. My first DC tig was something like £100 second hand. My current parweld ac was £450 used. I think my mig was around that price (used) also.
Gas price is neither here nor there really. If you're only doing a bit of welding, a 20l tank will last forever. If you're doing enough that it runs out quick, you're probably earning enough from welding that the cost of the gas doesn't matter anyway.
I guess the advice I could give is that if you're wanting to do welds on things that will be looked at closely - maybe things like hifi enclosures (?) then tig is the way to go. If you're wanting to repair rusty landrover chasiss then mig.
Speed is a real issue. The previous owner of my ac tig was doing alluminium work commercially. But boat hulls. He just found tig too slow, so changed to a spool gun on a mig. But that is even more specialist.