Short answer
Start with how you will use the van, then choose the buying route. A pre-converted van gets you camping sooner. A donor van plus converter gives you more control. A self-build can save money, but only if you have the time, space and patience to do it properly.
Buying a VW campervan FAQ
Should I buy pre-converted or use a converter?
Buy pre-converted if you want to get moving quickly and can find a layout that already suits you. Use a converter if you know your priorities and want the van built around them.
What should I check before buying?
Check the base vehicle first: MOT history, rust, service record, gearbox, engine behaviour and finance history. Then check the conversion: electrics, gas or diesel heating, water, roof, bed, seating and paperwork.
Do I need diesel heating in a campervan?
For year-round UK use, yes. For summer campsites only, maybe not. If you want spring, autumn or winter trips without relying on hookup, a diesel heater is usually worth specifying.