Are you American? Because here in Europe these are expensive and used cars are not.

Here are used moped cars for sale in my country, cheapest first

Here are used cars that require a drivers license

You see these moped cars driven by exclusively four groups of people:

1. Teenagers who can't get a drivers license yet but whose parents have money to waste on shit like this

2. Serial traffic offenders (usually DUI) whose license has been taken away and they can't get a new one, either for a while, or ever

3. Old people whose health is too bad to be allowed to drive a car

4. People who just for some reason can't pass the normal drivers education and exams.

They're pretty much just a legal loophole for most people.

I am a 30/40 yo city worker who lives in a small village with no train station and poor bus service. I don’t have kids, but like weekend getaways with my partner

Good luck driving to the city every day, or going on weekend getaways, at max 45 km/h. If you go over that, police will have your car inspected in case you've defeated the speed limiter. If you have, it's illegal to drive it.

I can see why you MIGHT think it's a good idea, but what you're really looking for in the scenario you imagined, is a nice tiny car that's actually allowed to be used as a car. I.e: Allowed to go above 45 km/h, available used for a sensible price, etc. Toyota Yaris, Nissan Leaf if it has to be electric, etc. The Leaf isn't even that tiny, but first gen ones are much cheaper than an Ami.