The 30k to me, sounds possible ish, but also hard especially without a helper.
Personal example, I’ve gotten many materials for free. Including several hundred square feet of hardwood floor.
But thinking through some basics of just tools needed, and being cheap- and also with an assumption that you have time, and land with wood. And assuming you find cheap / used tools but not junk.
Decent chainsaw: $600-$1,000 Alaskan sawmill: $120
Stuff to setup basic kiln house: $600
6-12 months wait on wood.
Planer: $400-600 Jointer: $200-300
Impact, drill, sawzall, oscillating saw, jigsaw, circular: $700
Mitre saw and stand: $400 Table saw: $200
Basic plumbing tools, pex or copper : $200
But when I start to think through things aside from that: If you start to buy materials…
I think it could be done, if you did a cement or block foundation yourself, and did very basic construction.
But my just off the cuff guesstimates, assuming 1500 sq ft ranch house:
Lumber for framing: $4,100 Toilets: $240 Fasteners: $500 Drywall: $1,500 Piping, fittings: $1,000 Electrical: $2,500 (assuming electric stove, and electric dryer) HVAC: $8,000 …. I start to see a hard time doing it for 30k, but, I’m sure there’s a way!
Leftover materials from a construction site have to be disposed... Unless you are a builder who wants a house and owns a truck and some land... It is a weird house, but built with pretty nice materials. I bought it from the nephew of the builder.
Second, blocks and bricks are a massive f-ing waste of labor when working as an individual since you have to handle them so many times. It's worth forming up 10yd worth of stuff and paying for a truck.
You can probably get it done under $30k if you are super cheap and only buy materials at auction and buy used tools.
A concrete truck would not even make it down my road though... and many of the blocks were carried in small bundles by 4x4 truck. Building a road for heavy trucks would probably cost as much as the house.
Foundations, walls and footings are cake because they're all formed, you just gotta finish the top. It's the flatwork that has lots of finished area for volume and is very laborious
It is worth it when you have trees that will otherwise go to waste, and you can get high quality appearance / live edge / etc cuts out of it.
If I had a lot of trees that needed to be cleared, and lots of time, I might be tempted to try using a portable mill in the 25hp range.
Bricks as an individual are miserable to handle. Even with tongs it’s tedious. When I was younger, I once reclaimed tons of brick from a house that was being demolished. More recently from a driveway someone removed. Both times in small amounts(<1,000 bricks) for specific projects.
I do know of a story of a restaurant, local to me, that somehow ended up needing to reclaim all these bricks that had mortar still on them. They invited over everyone they knew, gave out free beer and wine, and lots of eye protection, hammers etc. I can’t imagine it was an easy project but they successfully reclaimed it to build part of their facility.
Are you certain?
I've done plenty of DIY projects, and as soon as you start using hand tools, the risk goes up, especially if you include cutting or drilling.
Mostly no help
Not include tools or land but include renting an excavator to do the site prep and dig footings
Vinyl and drywall
How long did it take you?
What's the square footage and number of bedrooms / bathrooms?
Did anyone help you?
Did you include buying / renting tools in that amount?
Already own the land?
Interior / exterior finish levels? e.g. is it a cabin?