I think that the online Torishop should have a feature where it shows the price in the market as well as the price in the shop, to see the difference in the two. this would eliminate hassle and warnings for overpricing your items when posting on an items thread, and shows you how much it's worth after you buy it and want to resell it. this is combined with the percentages on the market that shows how much more or less you added onto the original price.

it might also get rid of most of the questions asked on the price check megathread