good camera, but the asking price is way too high

Canon 50D is certainly not the-state-of-the-art, but still an excellent camera. The 28-135 lens is very good and can satisfy most of your need. Because of the type of CCD the camera uses, there is a 1.6x factor, which makes the lens equivalent to 45-216 mm, more than enough for taking pictures of kids.

The price is too high, though. You could buy a Canon 50D plus the 28-135 mm EF lens in new condition from eBay for about $700 (search "Canon 50D" on eBay).

Hope it helps.