I picked up a real nugget.
Vauxhall Corsa D 1.3 CDTi 84,000 miles, 1 owner. Heated seats, heated steering wheel, auto lights, auto wipers, auto dipping rearview mirror. £3500
It had the standard known gearbox bearing issue which cost me £600 to get sorted, and I had to get the aircon valve replaced for another £200 with labour. But other than that its been reliable and a joy to drive.
You should find a good number of diesel vehicles at a good price since ULEZ. As long as you never plan to drive into Greater London then you are fine going for an older vehicle.