Hi Sam, you did it right :)
If you're building it yourself, I'm guessing the time/labor will be more of a factor than the cost of materials. Depending on how fancy the cabin is...
I'd start by reading some
books and watching youtube a lot to learn about making the type/size of cabin you want. Then you'll have a much better feel for what's needed.
I believe most building projects take 2x the money and 3x the time you thought they'd take.