Lots of people have already suggested stuff...so rather than duplicate, I'll add this: rather than spend $900 on a composting toilet, you can make one yourself with a 5 gallon pail, and a box built around it that supports a toilet seat on top. Put a couple of inches of wood shavings in the bottom, add wood shavings to cover each deposit, and it doesn't stink. I can vouch for this. Then, when the bucket is full, take it to your humanurecompost heap, dump it out, rinse the bucket, and repeat procedure. Put dry carbony stuff on top of the compost box deposit, and it doesn't stink either. Honest. Use cured compost around fruittrees and bushes, if you're squeamish about putting it around, say, spinach. Check out the Humanure Handbook by Joseph Jenkins. Recycle valuable "waste" nutrients, keep waste out of the rivers, and save $$$ on septic pumping. Closing the resource loop--this is permaculture in action.
I understand you are trying to go off grid but these are some things to take into consideration. I am not sure this has been mentioned or not, but I don't remember seeing these on your list. You need to budget money to dig a well or buy water catchment supplies and to purchase solar equipment. I would recommend finding out the cost to dig the well before you make your purchase, it is not something you can estimate without knowing where you will be. I know you are probably planning to use water catchment but having a well would make it so much better. Also even though you plan to use solar, find out how much it would cost to add electricity as they charge by the foot. If you can purchase land with a well and electricity you would be ahead of the game. Some areas have community water so you would not need a well but would need to purchase a water meter.
Try to find land that is not in a co-op or association. The politics and fees should be a deal breaker. Check with the county to find out how much your taxes will be.
Look at old homesteads that have dilapidated homes in them as these will be considerably cheaper. Something those homes are structurally sound and only need some repairs.
Invasive plants are Earth's way of insisting we notice her medicines. Stephen Herrod Buhner
Everyone learns what works by learning what doesn't work. Stephen Herrod Buhner
just a few thoughts. we have a small off-grid garden a few miles from home.
generator: get bigger if possible. 1200watt may sound good. i ve 2200 watt. and it s not enough. most power tools will require higher wattage to start. so a 600watt pump wont start and shut my generator down. plan for bigger or one that will be able to handle these surges. maybe look out for one small used to power smaller appliances
tools: get whatever you can and possible might need. there are so many projets you will run into. try to find used tools for small money. build stuff to get used to them and see what s missing.
water: you could build a slow sand filter. there is a thread here somewhere. these can be made portable. so you could have good quality water until you build the well. maybe look into water treatment with ozone (O³) and/or UV-C radiation.
toilet: could you build a composting toilet into your existing place? maybe with urine diversion... these can be made portable. if you plan to build a strawbale house, you would arrive with a working toilet system. convenient ...
solar: i started with two small batteries, charge controller and 50w panel. i bult it into our kitchen window and later brought it to the garden hut. so i gathered experience and started with a running and testet system
camper: would that be an option to get one of these first?
people: invest into relationships with like.minded people
business: can you start business now that you can continue on the homestead?