Foodle, I hope it doesn't seem like I'm busting your chops too hard.
I just hate to see people automatically go to primes when they don't need. In reality, even with f/1.2 lenses, most of us shoot at f/4 to f/11. With the T3i discussed in this thread, ISO 1600 has reasonably low noise if you don't underexpose.
BTW, I'm personally able to afford L-series zooms and primes. Still, when I sold my daughter my 5D MkII I actually suggested that she start with a prime, a 40/2.8 pancake, and then start saving for high quality zooms to cover the rest of the range.
BTW2, I've got over $6,000 invested in one prime and I'm considering a $13,000 prime, if I can come up with the cash without selling my M3. So, you see, I'm not against primes.
On a low budget, I agree, start with a good prime, but then start saving for L-series zoom glass.
Here's the progression order I'd suggest for the budget constrained with a full-frame:
- 40/2.8 pancake
- 70-200mm f/4L IS
- 24-105mm f/4L IS
On a crop sensor you'd need to go wider and I might even suggest an EF-S.