Even with mass production, the chemistry does not change. Limited Co supplies and a decreasing, but still present need for rare earths will only prop up prices.
Add to that new and exotic electrolytes and improved anode coatings, and it'll be a wonder if prices come down at all.
The existing battery packs have (vaguely) reasonable performance characteristics, I wouldn't think that manufacturers would adopt things that increase costs more than they increase performance.
(In fact I would expect them to mostly adopt things that cut costs without sacrificing performance)
we got a >50% reduction in price in last decade, while the chemistry stayed the same. Cost of materials accounts for a small fraction of the cost, and there's a lot more fat to cut in processing.
Add to that new and exotic electrolytes and improved anode coatings, and it'll be a wonder if prices come down at all.