Price Tiers - Enable/Disable

With price tiers, it would be great to have a tick box next to each one in the General Settings, where you set names, to activate/inactivate them, which then stops them showing in drop downs etc.

We have quite a few clients with only one or two price tiers but the customer drop down, sales drop down etc still shows all of them, and allows them to pick tiers with no pricing, which will never be used.