Most likely the lens that you are looking at included with the kit is the Ritz brand lens, (they used to be made by Sigma, I have no idea who on earth makes them now). They are not bad lenses, and will be fine for 90% of the people out there. As much as I would like to assume I am one of those 10%ers, I sadly, probably am not.
I used to work at Ritz (many many moons ago) and they are a good store, but it is possible to get some things slightly cheaper elsewhere (i like B & H) but the biggest advantage is getting to go into the store and actually look instead of buying over the net.