I reckon think a good quality pic sells the item better (even if only working on people's subconscious).
If you can manage a great quality home pic then all well and good, but I reckon a shop pic is better than a home pic which doesn't show the item off to its best. If you have described the item as new with tags, and your ratings are good, then I reckon stick with the shop pic as the main pic.
If the item wasn't new, I would be more likely to want to see its condition. but for new, don't bother I reckon!