That idea is similar in concept to something we've already looked into doing. It seems simple in concept, but it's actually a great deal of work to do properly. It would entail a massive rework of our online ordering system to implement it, which means two to three full months of at least one of us not working on the products themselves. That's simply not a viable option at the current time, since we're already not getting stuff done as fast as we'd like - let alone as fast as users want. We're spread really thin, so we're limited right now to options that can be implemented quickly within the framework we already have in place. :-(