said by jjoshua:
There is no way that you're getting a water softener that fits under your sink.
A real water softener is plumbed to your main water line and softens everything. It has a brine tank that you fill with salt to keep it working, not some mystery cleaning products.
You can get a reverse osmosis filter for under the sink which may help with water quality but these sell for a fraction of the price that you were quoted.
Sounds like a scam.
A whole house softener is only $200-500 bucks and a undersink RO unit with storage tank is like 150-300. For RO unit info check out "Air water and ice" website. Really good guys with lots of patience. While playing with your plumbing you could also install a couple larger canister filters for carbon and micron filtration for about 300 bucks.