£8000
Citroën’s 2CV is hilarious, ingenious, hugely practical, very comfy, stylish, fashionable and almost free to run once you’ve bought a good one. Unfortunately, that good one is not as cheap as it used to be, though you should still be able to find one with a solid floor/chassis for under £8000. However, if you do plump for a cheaper and rougher example, the chassis are only simple bits of flat tin so they’re very cheap if you’re prepared to take the not outrageous amount of time it takes to fillet the car and fit a one. If you do that, fit a galvanised chassis as the naked ones rust faster than MGB sills.
When bimbling in a forwards direction in a 2CV, you need to have patience, as the engine is a 602cc air-cooled flat twin.