That's what's referred to as " taking it to the extreme".Everyone has a story about buying a really inexpensive boat and sailing away to low budget bliss, but if you're bringing a large group onto a boat to live full time the cost and complexity will increase exponentially unless you're all hippies and like living out of each other pockets. Nothing wrong with that - don't get me wrong. I'm all for that. But someone with no boating experience who wants to house 4 people on a sailboat, and sail it places, needs to think long and hard about the safety and integrity of the boat and whatever systems are on board as well as the bare minimum living arrangements that can be tolerated.
All you HAVE to have is an intact hull, rig, and sails. Paper charts and a pocket GPS. A skillet and a bucket and some dog bowls to eat slop out of. That's all you HAVE to have. Anything more than that and it gets weird really fast. If the OP buys a typical 35' - 45' tired cruising boat (the kind he will be able to afford) it will be loaded with stuff that will either need to be repaired, or ripped out and done away with. You absolutely can go minimalist - you can go engineless (if the marina allows it - many absolutely do not) with no electronics other than a handheld VHF. It's perfectly possible to play Swallows and Amazons but working adults get tired of it after a week or so.
There's a lot of grey area in living aboard convenience and accommodations.
I've met sailors who wouldn't consider being without refrigeration.
A family of 4 lived/ cruised for 2 years aboard a 30' steel ketch( very close)
Each person finds their comfort level, as well as budget .
The determination I've come to is it will cost " all that you have" whether that's $1000 or a million , the goldfish syndrome persists.