Can't speak about the cost of installing a salt generator, as we got our salt system added in the pool construction for free.

Cost of chemicals for us (14k gallon fiberglass pool) is minimal:

Around eight 40lb bags of Morton's Pool Salt (found at Walmart for around $6 each): http://www.walmart.com/ip/Morton-Salt-Pool-Salt-40-Lb-Bag/16561292

Then approx. $50 worth of chemicals. Vacuum once a week (no trees around our pool).

$100 bucks did the trick for us last year. Hope this helps a little!

Expect a cell designed for up to a 40,000 gallon pool.
Assume it will be the same brand as the rest of the equipment.
Find it on line and add $200 to include the installation costs and something for the PB.
Figure about 14 bags of pure salt, be it Morton, Aqua Salt, or other decent brand.
Figure a bag or two every 6 months.
Figure Muriatic at $16/gal. The cell may cause up to a gallon a month, max but your first year will likely be significantly higher if you are building a plastered pool as new plaster needs the acid for pH control.
A cell based system is a chlorine pool. The advantages are not always cost based, especially right away. It is the convenience, the way the water feels on the skin and eyes, and then cost but that is usually after the 1st cell is spent.

Scott