I respectfully disagree and say that it IS feasible, it's just a lot of work!

I have been selling on eBay since 1999 (no pins yet however, only buy those) and yes, to run a lot of auctions at a time means hours of work beforehand, mainly taking and editing pictures. Selling on eBay is *work* and to sell more, you need to work at it more. There's nothing stopping anyone from working harder and listing more auctions, other than their own obligations.
To say that over X auctions is too hard so you get to skip steps is silly, in my opinion. As others have said, even with the best of intentions, we miss flaws or overlook things. I think that has happened to every eBay seller out there! (and if it hasn't yet, it will...just human nature). Using the same pictures over and over is bound to lead to this kind of problem at some time, because that picture does not represent the actual item you are selling.
I don't think it's a terrible sin, but I do think it is a risk, and if you choose to take it, acknowledge it as a risk and don't say "well I can't take pictures of my auctions because there are too many of them."