Bukkit

What is the enhancement in mind? How should it look and feel?
Player places spawner --- but nothing spawns (this is already done)
Player sets spawn type with egg (this is already done)
Player has to add "charges" to the spawner.  Ideally the charge itemID is configurable.  Some may want to use chicken eggs, or money from vault, or more spawner eggs.

The 3rd part is what I am looking for.  A way to limit how many mobs come out of the Spawner before it stops producing mobs.

Please provide any additional information below.

Quite an interesting suggestion. I can definitely see the value of this, and I do have some primitive spawner management already implemented (place spawner and nothing spawns). I'll definitely look into this though as I have gotten requests for similar things and I might just want to implement this feature on my own server.