How do I get steel & fab for only another $400 +/-? My welding skills are so bad I wouldn't want anything that I welded on the road.
I live in a two-light town and can buy pre-cut lengths of steel and I'm sure you can too. The last Dexter torsion axle I ordered cost $600 about 18 months ago.
I would encourage you to learn to weld. It's not magic. You know someone who welds and could mentor you. There are a ton of YouTube videos on welding using flux-core welders that really help.
This flux-core welder gets great reviews on YouTube:
https://www.harborfreight.com/welding/welders/mig-flux-welders/easy-flux-125-amp-welder-57861.html$150.
If not, have a welding shop fabricate one to your specs. You'll have a much better camper than one built on a cheap frame and a cheaper axle and tires.
Here is the chassis plan from my book. I've lost track of how many people have built teardrops using it.

It's built from 2 x 2" .120" steel--which isn't a challenge to weld.
And by the way, after twenty years of teardropping, my wife and I agree that a 5' wide teardrop is the perfect size for camping and towing. It also allows the builder to use 5' x 5' sheets of Baltic birch.
Good luck with your build.
Tony