Those batteries are not going to recycle themselves.
The thing is, a battery pack is made of thousands of individual cells. If a few cells fail, they can be replaced and the pack put back in to use in a different environment where the 80% of battery left is more than enough. I think it was Toyota who were using old battery packs in the vehicles they use to transport stuff around the factory. Or more likely, the pack can be repaired and then used in a solar installation where the a secondhand pack will cause less problems.
With regards the cost of cars, R&D is massive. I seem to remember a figure into millions to certify a new Audi headlight. Then there are crash tests, test driving of the vehicle is all types of conditions (very hot, very cold). Of course you have to maintain your dealer network, you've also got advertising, fines (dieselgate), press cars. The costs are epic.
Are we getting to the point that a car is a loss leader? And they make the real profit from extras/servicing etc;