What 13000? Here in the EU we pay around 3-3.5K for 15 kWh.
I am also in the EU and last year I have purchased a YIXIANG DIY battery case and 16 EVE MB31 cells for a combined cost of less than 2000 EUR without VAT.
It was shipped from China so I had to wait ~2 months to get it which is a disadvantage. Local warehouse stock was slightly more expensive.