Concealed, the G15 is a great camera for someone looking for a point and shoot. I've seen some great photos from it and is a great value for what it offers. It can be used fine for eBay but to get the best pictures you will definitely need to get the right settings.
The consensus of using a DSLR may be the right way, but the G15 has a great lens which helps it to stand out. Mentioned above are guys praising the 35mm f1.8 lens, and when it comes down to it the zoom lens on the G15 is f1.8-2.8 (if i remember right) so its ability to get some great depth of field even while zoomed in shouldn't be an issue.
I used to use a DSLR but now just use a P&S. But with all cameras, it a bit subjective. Just my 2cents.