What I think it would be a good feature is special promotional pricing.  For example, say you do high school senior portraits and want to offer a limited time discount for 1 month.  I would like to be able to have a sale feature built into a price list that I could just click a check box and take a fixed percentage off the price without having to re-create a new price list with the same products at a lower price.  If there was a built in time limit that would revert to standard pricing that would be even better.  Something like the coupon dates that are valid only between selected dates.  You could plan for a promotion, set it up, and the price list would automatically be adjusted accordingly.  I know I'm asking for a lot but, if it could be further customized to individual products it would be perfect.  To quote Ron Popeil, "Just set it and forget it".

"Throughout December, 25% off all 8x10 prints (prints only, frames and mounting at standard price)"

As someone else mentioned in another thread, I would like a warning to be in place that would let me know if the sale price would be below my cost so I could adjust accordingly.

I think you can just use a coupon and set an expiration date on it.

I can set a start date, an expiration date, and a minimum order but I can't say for specific products only.  I also would have to give out a coupon code, which just adds more mess to the checkout process. I would like to have a message on my front page (which hopefully I can do with the next update with page customization) that says "Sale on whatever" and just have certain prices change.  Thanks for the input though.