Good vans, i’ve not seen 10 year old T4 going for 5Gs mines a 8 year old.
Mine had FSH 2.5TD LWB with tailgate to keep the rain off whilst fafing about.
They’re prone to water pump failures, not sure of the cam belt change interval, but unless the seller has a proof of fitting then assume it’s not been done.
Problem i’ve found on the couple of T4 i’ve had is the oil pressure/level senses leak on high mileage ones and with the engine undertray it’s a bitch to spot where it’s leaking from.
Insurance wise i pay £320 per annum for Comp business use with max NCB
I get 38ish to the gallon on motorways/A roads if i rev it below 3000, much above this figure and economy plummets i’ve found to my cost.