Hi James,
There are MANY ways to build a well-built home which will last many decades or a hundred years or more. AND MANY ways to build with a smallish budget.
You can always start with smaller dwelling and build additional smaller units. THis way, it is easy to finish a single
project and move on to another. Learning from each one as you go...
Is your area of BFE in the US or other part of the world?
humid, arid, semi arid?
DO you want to have ways to catch rainwater off your roof?
Even if your home is even partially below grade, you can always build yourself a 'porch' to sit and play your guitar.
Here are links to several threads which may or may not work for your situation.
https://permies.com/t/17362/green-building/Adaptations-Pit-House-Earth-Lodge
THese homes are based upon indigenous cultural designs. These folks built their dwellings without money, I would surmise.
There are photos/links of examples of homes.
there are also photos/links of
Straw Bale Vaults which have been built in areas with cold winters and hot summers.
Look around the green building forums for earth sheltered home/wofati. ANd others. There are many folks here with much more experience than I have who can share wisdom with you.