I have been working on that for the last 6 years. My current retirement is almost exactly 1/10 of my high year salary. My goal was always to retire before the age of 50 and I finally did at age 49 because the program I was working on ended, and I had no bills and some nice property fully paid off.
In 2004, I discovered Peak Oil, and a new mission. I was determined to make this place as self sufficient as possible, reduce my footprint on the earth, and permanently cut my spending.
Now when I spend money, one of the primary considerations is will I get a return on my investment greater than I will pay into it. If not, I usually will not buy it. My wife and I are great cooks so we eat out very rarely. Usually only when we are off the compound for more than a day.
In 2010 I discovered Permaculture and had another epiphany.
I now have over 80 different types of perennial/self seeding edible plants growing on the property. And that is counting apples as one type even though I have six varieties and ten trees growing. Same with pears, peaches, Kiwi and many others. We are starting to put stakes with the plant names just so we can remember what they all are.
Just today, I went to this awesome little permaculture nursery and bought a Black Locust, a Heart Nut, Roman Chamomile, two Black Elderberry, two Service Berry (Canadensis), Lovage, Garden Sorrel, Salad Burnett, and a Angelica plant.
I've built a rocket mass heater in my greenhouse for a total of $37. Now I have a heated seed starting pad, powered by coppiced Big Leaf Maple, turning a problem of eternal maple sprouts into an asset, and the charcoal that is left goes into the garden as biochar, making the whole system a carbon negative experience.
I no longer: Till the soil, fertilize, apply herbicides, or apply pesticides. I am starting to apply measures so I will significantly cut down on weeding, and ideally become self mulching. This should leave me with the job of transplanting and harvesting, the rest of the work, through good design is done by nature.
It sounds zen, but if it's hard, your not doing it right. I spend a LOT more time observing now. I am learning to tell if a plant will grow well in a certain area by what is already growing there. For example; if Scotch Broom (an awesome nitrogen fixer) is growing there, it is a well drained soil. I've had lots of failures, and I cherish them more than the successes because I savor and learn from them. It's hard to describe this knowledge you gain by just observing. The closest I can think of is I am starting to "Grok" as described in Heinlein's book "Stranger in a Strange Land" (My all time favorite science fiction book).
I built a pond and used pigs to seal it. The pigs loved it, I now have a pond that fills with algae, which a wild Mallard pair have found who eat the algae and mosquito larvae. Watching it evolve and nature balancing it out was fascinating.
I'm actually planting nut trees so my grandchildren will have something to eat. How cool is that? To be honest, for us, things are coming together, and we are right where we want to be. The coming collapse could be relatively pleasant, you just need to have a small paradigm shift.
So now that the mumbo jumbo is done. I say GO FOR IT! What do you have to lose but some expenses?