Not only are there kits you can buy,,for exact models of van,,, but there are company's that will do the work for for around £1500 ,,,,, so let's say you buy a half decent second hand van,,,,5 grand,,,spend 15 on a kit,,and 15 for a company to fit,,,8 grand in total ,,,,only a small amount of what second hand campers can fetch,,,, and you could save money by getting a good deal on a van and spending less if you know what your buying,,,,and like you said,,,be even better if you know someone with the skills