I noticed that Alpha bay shows the purchase price in USD and then the price in BTC right below that. However, that doesn't include the shipping price so its kind of annoying if you didn't realize it at first and have to end up depositing more BTC. I think it would be better to display the total purchase price in BTC so that users can easily deposit the whole amount that they need and checkout seamlessly. Sorry if this has been suggested before.
I wish every market did this period. A few of the food vendors list it on their profile on agora but the majority give you squat until you are purchasing. On the bright side it makes me get about ten bucks more in btc than I need so every few months I can pool the leftovers for something extra