When we do our update later today with v173 of the addon, I added a slash command that you can use to remove a character from the shopping list for now – some day I’ll think about a UI element for doing the same thing, but for now this should work.
For example if you wanted to delete the character Johnny on realm Stormrage, you would enter the name exactly as it appears in the shopping list dropdown which is [player name]-[realm name]:
/amr delshop Johnny-Stormrage