Skoda Citigo IV Purchase

Moin. I would like to buy a Skoda from the dealer. First registration 08/2021 with 20000km on the speedometer and an almost full equipment. The dealer would like for this 15000 Euro – I find however for the age of the vehicle the SOH of the battery with 91% quite low. Since I have no experience, this is a good value or rather bad? The dealer says of course the value is normal. The car is check booklet maintained and I get 1 year warranty from the dealer Thank you in advance. Best regards Reima nn