My fiance and I are doing it ourselves. It's a tiny house and he has a few years of construction experience. We had to learn a lot on the fly, but it hasn't collapsed yet! Seriously though I bet you can do it, especially with a few mates.
Yep, that was my take on it as well. Have a few friends over every other weekend or so, some work, then lunch, beer (on me of course) and then do some more work.
I have very little building experience, but I was thinking of consulting people and YT videos, as well as people online for specific things. Heck, it can't be that hard. I mean, I've seen construction workers work, it's not rocket science. Sure, I might get some things wrong, but even if I'd have to redo them, it should be a lot cheaper in the end, compared to the price of a house.
I'm good with my hads, maybe that's why I have this notion, that I can do it.