You can do cheap if you want like the $30 biab on stove method.
If you don't mind investing a little bit extra you can set yourself up better. My setup is $50 for a 50L pot, $35 for a three piece, $20ish for the elbow and threaded nipple to act as a pickup when draining the wort. $10 for a bag, $3 for a stainless cooling tray and $3 for a paint stirrer. Nasa burner, reg and hose was about $65, and new gas bottle was $50.
Insulation i have a few windshield covers and a thick blanket that at most during winter drops 1.5 degrees over an hour mash. I just tie on all the insulation with rope.
So all up around $240ish. I would reccommend going the 3 piece over the 2 piece valve just because the three is far easier to clean.
I've mounted the burner in an old car rim, just welded on some legs to raise it off the ground which was all free