Doug, this is just my opinion...but I would not use a digital camera for the purposes you mention ( ebay, photobucket, websites etc)
There are just too many issues that tend to make the picture subpar.
(Lighting, Flash, Glare, Propping the cards up, etc.)
I've got a pretty good digital camera but I have never been happy with the results.
I know you mentioned that you don't have a lot of room for a scanner...but since these are all USB connections, just hook it up when you are going to use it...and hide it in your sock drawer otherwise
I have a Canon 4400F that was only about $100 and it takes great scans (even graded cards with no glare). I probably only use it once a week...and would have no problem storing it the rest of the week. (although I do have room in my case)
So, just my opinion...enjoy either way!