In the last couple of years, my mate has had a 5.1 panel van we got at auction still under warranty & converted with two captain seats plus rears with new leathers, put in side windows, changed the cluster, fitted cruise, remap, MFSW, tailgate, Kenwood VW unit, spoiler etc. He sold it and recently got a 2006 T5 with 167k on the clock, done pretty much all the same but has done a facelift. I put highline clocks in, cruise etc and he has recently put a rock'n'roll bed in with units.
It is purely down to budget, buying one 'sorted' already is a fortune and less fun if you want involvement in the process.