Is this killdozer?

no it's ruledozer

Man, the cost of used construction equipment and raw metal stock makes this yet another unattainable goal

Basedozer

Gaydozer

Salvage is remarkably easy to get your hands on... remember, it costs money to store scrap material, so some people are more than happy to give it away

... bcs a 'bullruler' is prob something else ...

would be killruler tho if we're lore accurate

Large construction equipment has less security usually than a mid-priced sedan. A complete setup for welding iron and steel can be had for under $250USD. Many older farms have scrap metal laying around.

We need to revive the entrepreneurial spirit in order to make these dreams come true.

Love the spirit, reality check on the feasibility:

You can buy a set of all the major heavy equipment manufacturer's keys off amazon for like $50 (and you should). However driving said heavy equipment is actually a difficult skill (double clutching is so hard wtf) and transporting said equipment to a place you can reasonably work on up-armoring it is a real challenge. Additionally, all heavy equipment rentals have a suite of monitoring equipment onboard that updates to the rental agency 24/7 and includes realtime 3D orientation and GPS tracking, some even have remote kills in case of theft (tho that is uncommon).

Welding is a lot more complicated than that. A $250 setup is going to be a 110v/220v combo self-shielding wire feeder/stick welder, and that is NOT going to cut it. Equipment like that can barely run 6010 so there's little chance of you getting a good root pass in. They're just hugely underpowered. Any welds you make will be cold and lacking depth of penetration (the real term). They'll pop apart under a firm sledgehammer blow. Additionally, the actual "welding" part of welding is a very small part of the process. Prep and fitting are (rule of thumb) 95% of the time you spend, and both require a great deal of expensive and specialized equipment all their own (or I admit, a good angle grinder, lots of time and extremely patient neighbors). Killdozer was built in a pretty comprehensive metal shop, and recreating it without at least an overhead track hoist would be pretty dang tricky.

And not to belabor the point, but while scrap is relatively easy to find, nobody has good steel just laying around. If you use the kind of metal common on farms you're going to wind up DIYing an even uglier and less bulletproof cybertruck, because modern .556 can punch through even 1/2" mild steel plate like it's not there (and at least cause spalling on thicker slabs). But if you've got some 2"-3" plate, for example from old equipment mounting bases at a shipyard, that'll keep you safe from small arms. Ideally though you'd want something like AR500 (which you cannot afford) to keep from overloading the drive on your equipment before you even roll out of the shop, since a 4'x8'x3" mild steel plate is 2 tons and you'll need a couple of those just to protect the crew cab.

Bottom line, Killdozer was the product of a different age and economy. It's just not feasible to reproduce it on a citizen scale anymore.