Add a button that when clicked, incrememnts the entry count by one (quicky adding duplicates with one click)

somewhere between '+ Collection' and '+ Wishlist' I would like to see a simple '+1' and '-1' button. I regularly wait to add all my bulk cards from a single set until after I believe I am done purchasing packs en mass. I also try to keep at least 2 loose copies of every card I can in the event someone wants to trade. Having a button to quickly add 1, add another, etc. and scroll down would save me a TREMENDOUS amount of time when doing this, as opposed to the current method which usually involves opening a new page and manually typing in the amount of cards I am adding, then navigating the cursor to go back and scroll back down or close the new window.