The biggest cost in moving off grid is purchasing your own land. You can camp on your land whilst you construct your home. You can erect a shed, or park a caravan, or pitch a tent. You can purchase & install a garage & slowly convert that garage into a house.
Next expense will be rainwater catchment tanks to catch rainwater
from the roof of your dwelling. Make sure you have tanks to supply water to
your home, & separate tanks for watering your garden.
Starting a garden & keeping some chooks & or ducks is a survival must. The world is going to suffer food shortages in the near future, some countries are already suffering famine & people are starving, so it is extremely important to become as self-reliant & sustainable as soon as you can.
If you can’t afford a rainwater catchment tank right away, then find some other containers to get you by. We started off catching rainwater from the kitchen roof in fruit juice 44 gallon drums when we started in the Territory. Now we are in New England NSW.
I recommend you get composting toilets, but if you can’t afford these from the start, then construct an outside dunny & install an ash can toilet. Use mulch or sawdust or wood ash in the toilet, & when it is full, bury it in your garden area to compost/breakdown.
Grey water from your shower & the kitchen can go to the garden. We have grey water trenches under our garden beds. The urine from our composting toilet also goes into an underground trench.
Electricity is not compulsory, but it does make life easier. My wife & I lived an 18th century lifestyle for over 20 years. Our shower & toilet were outside, we did the washing of clothes & bedding in a copper over an open fire, I made a Coolgardie safe & we dried a lot of our foods. When we needed meat I hunted with my .20 gauge flintlock fusil, it was less expensive than using a modern firearm.
Now we are living in a larger house just down below the cottage that I first built. Now we have solar power, so we have a fridge/freezer. We bottle a lot of our garden produce & we still dry some of our foods & herbs. We cook on a wood fired stove which also heats our water. Water is gravity fed to the house, no pump required. We have a wood fired heater to warm the house in winter.