Spyglass Upgrading (New Cartographer Trade)

The current Spyglass has limited zoom, sure you can see several blocks, but what if you could see even farther? You could spy on your friend's base with no chance of being spotted, or spot those pesky Ghasts before they become a problem! I propose, that the Cartographer villager would occasionaly have a new trade, which would allow you to trade in a Spyglass, in addition to some emeralds (darn greedy villagers) to "upgrade" your Spyglass to level II or III (the level would depend on the villager, similar to how trading for enchantment books work). The level would be displayed below the Spyglass' name, where it would normally say how much damage an item does. Each level would increase the zoom by ~50 blocks.