What it cost:
We borrowed a demo hammer from a friend and also truck to haul all the bricks to the dump, so maybe $5. Otherwise, you could rent a demo hammer from Home Depot as well as the truck to haul your debris.
One piece of 3' x 5' durock - $10
Hand-full of concrete backboard screws - $0, I had a box leftover from 2004 when I re-tiled the bathroom in my condo.
Scoring tool for concrete board - $0, had the tool from 2004 remodeling
Stone work: $200
90 lb back of tinted mortar (bought from same place that sold the stone) and 2 boxes of El Dorado stone veneer (about 10-12 sf in each box from what I remember, I had quite a bit left over) - $185, includes a 10% coupon I found in one of those coupon magazines they send every month.
One pointing trowel, and one standard small square trowel - $15
Drywall mud and clear caulk for patching up the wall near the stone - $0 (again, had the stuff left over from other projects).
Firebox clean-up: $19
One can of black high heat paint - $13
Two new handles - $3 each
Two 8 foot lengths of 1"x8" select pine - $30
One can of stain - $6
Polyurethane coat - $0, have a can from a previous project
2" x 4" to mount to studs - $0, left over lumber in the garage
Nails, screws - $0, we have plenty of this stuff from other projects
Total Cost: $270