Samsung galaxy book 4 battery availability and cost

I am looking for cheaper options to replace my dead battery lg gram i5 10th gen. The issue with lg gram is the battery +replacement service costing me around ~14k. I see no point in it.

Alternatively i  looked at galaxy book 4 i3 8gb version for light use and it costs around 30.5k with all discounts.

But wanted to know how much the battery costs and what is the durability of battery that comes with this laptop?

I see these slim model batteries not available freely in the market and i assume they lost for 3yrs, 30k might go waste if part is not available.

Any experience and suggestion please.