We are seeking around 12k per van, and there is no VAT applicable. In today's climate, not many people would want to think about spending their money, but, there is an alternative some might like to consider if they dont fancy spending such a chunk of money:
12k will cost, over 3 years about, depending on your credit score, around £360.00 a month. [Or you could do it cheaper if took a loan out over 5 years, or you placed it on your mortgage perhaps]
Without wanting to get into the age-old " how much a day can I earn" type discussions, but you could easily earn a sensible income if you have the right sort of work, on your own. If you work in pairs, then obviously your income rises accordingly. And of course, theres no hassles with making your water in your shed etc. All you need do when you return home from work is to just plug the water main into the van's water manifold, and walk away in readiness for the next day.
At the end of the loan term, you'd be left with a van of some 6 years old, with a reasonable residual value too. And your running costs and loan should be tax deductable, etc but do check with your accountant.