Absolutely put more of your cash into the lenses. As much as it hurts to think about, you’re probably going to trash the body long before an equally priced lens. A good lens will also hold its value relatively well, even when the lens model is updated. (Nicer used Canon EF lenses aren’t easy to find deals on since they’re quickly bought; I’m constantly searching.)
I’m a Canon man, and I’ve tried some of the kit lens. They’re absolute crap. Images appear soft and with an annoying amount of chromatic aberration. Sigma’s lower-end equivalents such as the Sigma 18mm-50mm 3.5-5.6 DC Zoom are similarly poor. This crop of an overhead florescent light in the corner of a much larger frame shows how extreme the chromatic aberration can be with the Sigma model.
While admittedly blown out, there is a very distinct purple color cast in the areas directly above and to the right of the lighted area. This was shot at f/3.5, 1/80s at ISO400 at 18mm (x1.6 sub-frame conversion).
I’ve been completely satisfied with my Canon XTi and Canon EF 28-135mm f/3.5-5.6 IS USM. The 28-135mm is a great general-purpose, budget-friendly image stabilized (IS) walk-around lens. Image stabilization is well worth it, as you can get away with many hand held shots in low light or moving subject conditions which ordinarily aren’t possible.