We only spent about 500 usd/pp/month and were really comfortable. We had most of what we wanted and ate well. Learn how to cook, don't buy junk food and the best things, like surfing, are free. I made money on the van since I did all building and repairs myself.
Doesn't lend much gravitas, but it was a good life and I hope to build another campervan to use in the future. I'm quite scared of this in America though with our culture, crime, and police. I can also believe it is certainly not for everyone.