Ex-rental e-bike
 

I would like to buy a mbt e-bike.
They offered me an ex-rental bike: Haibike SDURO HardSeven 3.0 (with 1000 kilometers) size S (because I'm short) for 1500 Euros.
Is this bike worth it?
What should I check?

Can I offer a lower amount of money? How much?

Experienced individuals on endless sphere "assume" the battery on a used bike is worthless unless they know its history. Part of the reason is Lithium batteries can be damaged considerably if operated until they are at minimum voltage (although the battery management system should prevent this), get too hot, or even worse, too cold. That bike new would be about $2,500 in the US.The year of manufacture and price in your country, the cost of a replacement battery, and the condition of the bike all factored for COVID will determine whether it's a good deal. I would be very wary.

My guess is that rental companies put crummy batteries on the bikes they dispose of

So you think it worth no more then 1000 Euros (abount 1175 dollars) because the battery replacement costs about 730 Euros (850 dollars)?

IMO, that would be a decent deal if the bike doesn't look trashed. Unfortunately rentals are often abused because the operators aren't knowledgeable and/or don't care. I've seen individuals do all manner of abuse to rentals (cars only though; never saw a rental bike for sale). Going to be an unpredictable venture.

Rental bikes are not treated as badly as rental cars. Usually one day rentals, plus, if it's a bike shop, they certainly will not sell you a damaged bike if they want to stay in business. The battery should be alright with a thousand km. that's only about 30 recharges.
If an economical hardtail is what you're looking for, the price is not bad. Give it a good look over. See that it shifts smoothly and the brakes work well, etc.

BTW, seeing as you want a small frame, many of the clearance sellers have small frames at reduced prices.
Hibike
Ridewill
etc

So is 1500 euros a good price? or 1000 euros?
Regards,
R.

My wife bought a used Trek ebike this summer. We had to replace the battery after about a month.

We got ours for almost half price. If yours looks like it's in good shape, and you like the bike, then I'd offer half the new price, and see what they say.

But don't be surprised if you have to replace the battery. The price of that one seems really high, but maybe it's fancier than ours.

1500 is a good price if in good condition, but 1000 is better. It depends on what you feel comfortable paying. I would consider 1500 the starting price, then as I inspect the bike for any damage or worn parts I would calculate deductions. The ex rentals in my area sell very fast, so, I would not wait too long to make a serious offer.