Yes, 800 is correct for the start kit, but add a telelense (which you'll need that costs around 600 at least), new bag, new tripod, battery grip, 4 batteries, mem card, filter.. you easily reach 1500 USD don't worry
As for the stock 18-55 lense, honestly, it is crap. nikon's D50 or D70 have better stock lenses.. so if you want to only have a single lense, it's not a good idea to just buy the XT with the 18-55.. so again, easily well above those 800