Wait for battery prices to come down?

Looking at getting into solar & battery. I have a detached garage connected via 80A fused mains supply. Garage has east /west sloped roof, and looking at around 8-10 panels or so each side (so 16-20 ish total) would want bi-facial as well. Would also look to get batteries and want at least 15kwh usable to cover 90% of days, ideally 20kwh would be 99% coverage.

Cost of the above I think would be about £13-15k so payback around 10years (assuming no profit from system). Of course batteries are a major part of the cost so I was wondering. Is it worth waiting a year or so to get cheaper batteries? Or should I just bite the bullet and go for it?