DIY floor pans.

So i have ran into another problem I found large amounts of rust in my rear passenger side floor pans it travels all the way to the seat mount and up the tunnel as well. Unfortunately I cant afford to replace the whole thing and this single pan isnt gonna be big enough i dont think so I'm thinking about doing one myself. Just buy a sheet of sheetmetal and try and form and mold it to match. Here are my questions. What gauge sheet would be best? As far as making the corners is it best to cut a slit and fold it like a box? Should I try to do it in one large piece or in sections and weld the sections together? Thanks for your help and please dont reply "just buy them" because I cant afford them I have looked. Unless i can find some used that someone has cut out of a parts car. The whole pan is like 500 plus 150 shopping I just cant swing that. Here are some pics if it helps.

View attachment 1715503453

View attachment 1715503454

View attachment 1715503455

View attachment 1715503456

View attachment 1715503457

View attachment 1715503458

View attachment 1715503459
Well, this reply is gonna make some heads explode, BUT...
Since you need to keep this budget friendly (and there's no shame in that, we've all been there) go to the auto parts store and get 2 or 3 fiberglass repair kits. Line the floor pans, double it up where you have rust holes, triple it up if it's a spot you need to drill a mounting hole through. Contour it to the factory metal. Lay a bunch of fiberglass strips in. Make sure the floor is clean, I mean REALLY CLEAN before you start. This is a temporary fix. I repeat, this is A TEMPORARY FIX. But, take $55 every month and put it in your sock drawer. Don't touch the money, no matter what. Next April you will have the cash to buy the floor pan replacement. Do it the right way then. And, maybe don't take any passengers until you get the metal floor pans in.
Good luck man.