It’s not possible to give any sort of worthwhile guarantee on a 7yr old van with 80k up, never mind a write-off. Most aftermarket warranties aren’t worth the paper they are (or aren’t) printed on. Spend as much as you can upfront on the best vehicle you can afford.
Also as a wee negative, I’d be very wary of buying a used van at all. As a general rule businesses don’t get rid of commercial vehicles just because they fancy a change, they get rid of them because they’re done, no longer economically viable. The Renault Traffic is not a particular good van either, they suffer from loads of expensive issues particularly engine and gearbox problems.
The best used vans come from large fleets who offload at set times and maintain them well. Ex BT, NHS and possibly AA and RAC. I bought an ex NHS VW Caddy SDi and it was a genuinely good wee van that served me very well. I nearly gave up with looking at used vans at the time as everything I looked at was utter trash and that was with a strong budget at the time.
Unless you absolutely must have one I’d favour a large MPV or estate car instead.
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