light gives you far more bang-for-the-buck than does fast glass or the latest digital camera or 300/2.8And reading some of the articles and seeing what kind of results you can get with just a basic off-camera flash, I'm can believe it. Remember that even though DSLRs have far greater image quality than the standard compact, they still won't work miracles; if you dial in the exact same setting on a DSLR as on a compact, they will expose the same scene with the same amount of light. The difference lies in that 1) a DSLR can use much higher ISO without the image turning to porrage, and 2) you can change lenses on the DSLR, thereby getting a larger aperture, which lets in more light.
Now, you can only get so much from boosting ISO sensitivity and a larger aperture. And on top of that most kit lenses have apertures in the same range as compacts. Add to that the fact that a lens will almost never be sharp when it is at the widest aperture-setting, and you're gonna have trouble getting sharp images in low light.
This is where the flash comes in. Pop off a flash and the extra light allows you to close up the aperture and raise shutter speed.