Definitely agree - I do this frequently, particularly with gems!
Sororia: There is a deposit, but it's only available in Decorate Mode. That said, I'd like to see it in regular mode.
Muncey - while I agree it's not that hard to go max, then subtract one, "all but one" is an option I can see people using frequently (I know I would), and when it's used frequently, it can be a hassle (not to mention the fact that setting the amount to take out of a box can mess up sometimes too...) It's certainly a bottom-rung update, but I think it's something that in the long run would be quite helpful in making it easy to keep your house design organized the way you want it.