I have a 90 td5 hardtop with privacy metal to rear [ok its a van]
go for well maintained rather than low mileage
servicing is expensive so avoid trucks with incomplete history backed by invoices
road tax is less for commercial versions, td5 available with 3 front seats, later transit engined 90's only have 2 seats
td5 has a good record of reliability but later td4 with transit 6 spd box has ongoing 'issues' with gearbox
tyres are not cheap but should last 60,000 miles per set
td5 returns 28-32 mpg if lightly driven but this plummets to 18-22 mpg if thrashed
low teens ££ should buy you a really tidy hardtop or pick-up, station wagons are more expensive, avoid electric windows/air con/abs/traction control- just something to go wrong
heaters are rubbish - take 10 miles to get hot
make sure it has a tow hitch but avoid a winch unless you can't manage without
tdi versions are best for diy but getting old now
main dealers very hit and miss, many miss, rather sell a loaded RR Sport to a WAG with all the bling than deal with impoverished peasants