Is your feature request related to a problem? Please describe.
You can't see the price history of an item in the sell tab unless you have the item in your bags. Why?

Describe the solution you'd like
Should be able to see item history of an item even when it isn't in your bags. For example if you've added it to the favorites selection.

Describe alternatives you've considered
Always having said item in inventory, which isn't exactly a great alternative if I end up selling them all.

I don't know if it is possible.. but a "Historic Price" frame when you are in the "Buy Tab" (Red square) or a second window with the "History from selected item" (Green square) could help.

Then you can browse the auction house and you see if the price is high or low.

Available in alpha 448, right-click any result in the "Shopping" tab to view a price history