I expect a rudimentary fit -- make sure the saddle is (can be) adjusted to me, and I do think the shop should be willing to swap out a road bike stem when needed.
Anything else is gravy or negotiable. I've never personally run into a discount on things you buy with the bike, but that would be a nice benefit. Especially since all my bikes get their own water bottle cages, a blinky or two, a pump, patch kit, spare tube, multitool, and a seat bag to carry the last four. REI offered to put fenders and the rack on my daughter's bike -- that was very nice!