My false bottom in my eBIAB keggle setup is a bent pizza pan from the Dollar Tree, with a piece of surplus teflon insulated wire (silver coated copper) to pull it when the boil starts to get it out of the way.... it keeps the bag off the element and RTD thermocouple probe for the pid.
Mine is bent in a "L" shape as the element itself takes the load from the pan on the other side.. it could just as easily be bent into a U or have stainless screws and nuts added to raise it of the bottom.
Nope it's not stainless.. nope, it's not rusted. Whatever keeps the pizza from tarnishing the thing seems to work for wort.. don't judge me!
Brewing can be done on all budgets. With a little 'backyard engineering'. That's mostly how my rig works, but I am thinking and planning brewery 2.0 [I'm at v1.5 now] with the philosophy of easy to clean and reusing equipment as much as possible.
A radiator out of a car makes a great chiller, but this is going too far for me. I found a white paper where they analyzed moonshine off the street and found all kinds of interesting toxic materials and automotive fluids... the benefit of being in the analytical sciences!
The guy who submitted a barley wine in the Furious competition...
Suit yourself. Commercial false bottoms are a pretty poor investment compared to what you can use your money for. Especially with BIAB as you are using the bag in the role that a quality false bottom would be needed on a traditional grain bed filter. You obviously don't even need holes in that false bottom, in my setup with the pump recirculating I'm convinced it is better that I don't.
I like to build stuff, so even when it's slightly more expensive to do so I usually will.
I'm setting myself up to machine up Tri-Clamps/Sanitary pieces and silver solder them. It cost me $15 more than buying them commercially but when I need that second set I'll recover the cost.
And overall, yes I have saved a lot of money and learned quite a bit.
