Why separate viewing and selling items?

I have been playing for less than 2 weeks, so I'm fairly new to the game, but this bugs me. I cannot understand why on earth there are 2 different interfaces for buying/viewing items on the Market and for selling them. Unless I know every item I need to check on and am ready to take notes, I have to go back and forth and back and forth. Each time that requires summoning and dismissing my retainer. This feels the height of tedium, and I'm hoping there is something easy I am missing. I cannot imagine myself spending time every day dealing with that unnecessary mess.

I guess you haven't noticed the little icon to check what the item is selling for on market in the same windows you use to put your price. It also shows the item sale history btw.

See? I knew I had to be missing something. Thanks much for replying!