Thought I'd update. I was delayed weather and a minor foot injury that kept me from progress for a period...
I started collecting pallets, and have used a fair few pallets, but word got out and a friend and a relative had wood they were happy to get rid of.
Also, At the pallet dumpster at the County Dump, I pulled a crate that must have been used to ship a piano? Nice wood, all big planks, some 4x4 pieces in there too that have come in handy.
I've spent more time breaking down pallets and pulling nails than anything else, it seems.
I've exceeded my $35 budget, but so far not by much. $12 approximately in nails and screws, $10 for wheels I haven't put on yet, $10 in lumber, $15 in hinges. I also spent $15 on a new staple gun when mine broke the day before getting started, I'm not including that since I would have replaced it anyway and it gets use around here.
The one thing that I wasn't able to canibalize or scavenge thus far was sufficient lumber for a frame. I was able to make do with a fair bit of wood form the Cull Bin at Home Depot, and the Habitat ReStore...Good stuff can be found if you're a little open minded, and don't limit yourself
I will say that I'm not a contractor, carpenter, engineer, artist or poet. I don't have a shop of all the right tools to make things go quickly. I don't even have a workbench, and have been doing this on my deck using a couple pieces of outdoor furniture when I must.
My tools list for this project is includes: Cordless Power Drill, hand saw,
Wal-Mart brand Jig saw with a nice Bosch Blade for quickly cutting wood, clamp, hatchet, Claw Hammers (I have a couple, big and small, both have a niche but you could of course use one,) rubber mallet, wire cutter, file, hand plane and miter box.
The most important tool has been my cordless drill. I'd recommend a quality one before starting out. Mine is a Makita. I used screws as opposed to nails in most situations. I understand that nails are preferrable because under stress, they'll bend and not shear, but I prefer the ability to back screws out, and since I'm working with reclaimed wood that sometimes isn't 100% consistent after its reclaiming, its nice to drill pilot holes and not worry about splitting.
Second has been my Jig Saw.
https://www.walmart.com/ip/Hyper-Tough-3-5Amp-Jig-Saw/199349530. Nothing fancy, but with a nice blade (this is mine)
https://www.lowes.com/pd/Bosch-1-Pack-10-in-T-Shank-Carbon-Jigsaw-Blade/50247181 it moves quickly through wood. Combined with my trigger clamp
https://www.homedepot.com/p/DEWALT-6-in-Medium-Trigger-Clamp-DWHT83139/204389199, and a piece of wood to guide the blade guard, straight cuts are easy enough.
Hatchet and hammer are great for breaking pallets down. And, a file to sharpen your hatchet. Also, a wire cutter to cut stubborn nails that don't want to be pulled.