Ball-park $ for mud bed ....
Sandy - I had the same situation it sounds like you're in (ripped out 1 piece fiberglass shower, redo with tiled walls and floors) and I ended up putting in the mud bed myself using the Goof Proof / Quick Pitch system (I think Mark E is the mfr, just google it). I was recommended this by our MN version of Century Tile (I used to live in Chicago). Had I discovered this forum earlier, I might have tried the Schulter / Kerdi system a lot of experienced folks here seem to like (and will probably try it on the master bath reno teed up for next year), but I'm happy with the results. I was very hesitant to make my own pan because I didn't think I could get the slope right, but this Goof Proof system somes with plastic "spokes" you lay in the shower base and use to shape the concrete slope (spokes are higher at the perimeter, slope down towards the drain). I also bought a $5 DVD that walked me through the whole thing. Easiest part of it was the "mud" - specified a very dry mud mix so it wasn't nearly as goopy as thinset/mortar mud for when you get to the tile part. Cost for mud, kit (pan "spokes" and curb forms), liner, etc was $135 which is less than half of Schulter (and another $5 for a mud pan from Home Depot) and I did it over 2 days (only an hour or so each day). Not nearly as scary as I thought it would be, and my husband now brags to his buddies that his wife put in a mud shower pan. Anyway, just my 2 cents, but since it sounds like you're already pretty experienced with the cement board and tile installation, I'd encourage you to give this a try (or at least think about it). Good luck.