Lodge cookware is fine and cheap, I have a few sized pans from them acquired over the years and are still going strong, my only complaint is that the handles on them are very short. I also have a no name random cast iron skillet I got at big lots like 15 years ago that is also just as good as the day it was purchased. You don’t need to break the bank on getting cast iron pans—they are literally just a hunk of iron.
You should however figure out why you want cast iron. It is true that it is basically indestructible, but it has certain properties that can (slightly) affect cooking (specifically it retains a lot of heat for a long time and also heats incredibly unevenly).
Unclad stainless steel is basically the same as cast iron in that it doesn’t have artificial coatings and is nearly indestructible, but also heats faster and more evenly, is lighter, but doesn’t retain heat as well.
But seriously a 12 inch lodge pan is like $20 bucks and is basically all you’d ever need to cook most things
Also biggest advice: you dont need to baby your pans, just cook in them regularly and clean them afterward—they are at the end of the day giant hunks of metal that are heated.