I haven't seen battery price quotes for retail customers for a while now, everybody I know who wants one has one. But not too long ago a battery bank including installation was easily in the range of 800 to 1000 EUR/kWh of storage.
Battery storage may become a bit of a no brainer from a purchasing price point of view, but I don't think it will actually be more beneficial for people, especially if BEV adaption continues at a similar rate and bi-directional charing becomes widespread
You can put together a simple and fully independent solar island with 5kw/h capacity and 7kw nameplate generation for $4100. This is a plug and play system, with zero wiring and no knowledge needed. For the idea of the kind of profit margin that includes for the company, their "smart isolation switch" is $1k. Jackery has several competitors, and all of their build quality is pretty good, and the warranties are acceptable.
20kw/hr of just storage is about $10k. Every one of these companies also has standard DC input ports for bring your own solar panels, because their panels are overpriced.
The 8-Bit guy has been using such a system to maintain his studio. It is reliable, uses cheap solar panels. This stuff is commodity.
Battery storage may become a bit of a no brainer from a purchasing price point of view, but I don't think it will actually be more beneficial for people, especially if BEV adaption continues at a similar rate and bi-directional charing becomes widespread