One reason to brew is the feeling of pride you get when you hand your buddies a brew you crafted and get "wow, that's good" as a response."
Stainless steel is more durable than aluminum.
My advice is to save your money and buy quality items to begin with. It's no bargain to buy something and then replace it with a more expensive and better quality item because the original just didn't get the job done very well. .
Another difference between stainless steel and aluminum pots is their thermal conductivity. Compared to aluminum, S/S takes more heat to get to a given temperature, but the flip side of that is that S/S pots hold that heat longer. Less btus required to keep it at a boil.
I do BIAB (brew in a bag) and mash my wort in the pot. With the flame out, I cover the pot with a pair of old insulated coverall for the hour it takes to mash to help keep the mash temp as close to specs as possible.