Enchantment Enhancer - a balanced way to enhance enchantments?

A workstation block that will, as named, enhance enchantments.

1. Would have to be very expensive to craft.  Could require a boss drop to craft (like a nether star for a beacon) and an enchantment table, possibly more.

2.  Needs more bookshelves around it than an enchantment table.  Or perhaps another block around it?  Such as diamond?

3. Once a tool/weapon/armour is put into it, and payment is given, one and only one enchantment can be moved to one more than the cap.  Eg.  Fortune III can become Fortune IV, Smite V can become Smite VI, etc.  But, once it has been enhanced, said item is enchantment locked.   It cannot be enhanced again, it cannot have any other enchantments placed on it.

4. Payment in the table should be costly.  Tens of levels, blocks of resources. etc.

5. Tool/Weapon should have a different colour tooltip to indicate it is an enhanced tool/weapon (or a different enchantment sheen colour)

6. Cannot be disenchanted.

By making the process expensive to obtain/achieve, as well as limiting the amount it can be used per item, it can keep the system from being abused, and make players decide what best suits their game-play.  Also makes the items even more precious than a typical piece of tool/weapon/armour. (And oh-so-more painful when they are accidentally lost)