The cheapest EV would be a BYD Surf, but unfortunately you cannot find used cars of these yet in Europe. Too new. Eying those for a while

That's not the cheapest, at least in France the cheapest new EV is the Dacia Spring.

Of course if you look at the used market, older models like Renault Zoe can also be found for cheap... But considering EV technology have been evolving fast, I wouldn't buy a model older than 5 years old.

I also wouldn't want anything that doesn't have a CCS2. All my small electronics are finally USB-C, I don't want to deal with obsolete plug types and adapters again.