Enchanting and xp

Enchanting whit the enchating table is a mess. Even with a xp farm made with spawners takes a long time to enchand a full gear so i propuse the following solutions.

• The xp required to achive a level have a lineal increse, taking the same time to achive level 2 from 1 to 30 from 29. The amount of xp can be the xp required can be the xp required to 11 from 10.
• The tiers 1 and 2 of the enchanting table need to increse tier enchanting level.I suggest 1st level 1/3 of 3rd level and 2/3 for 2nd level, rounded down. More bookshelfs not only give you a higher enchantment also give you a descount in lower enchants.
• You can use other gems to enchant besides lapiz, depending of what gems you use you have a plus in enchantability. This give more used for diamonds and amatist.
• Increse the max level of enchant, from 30 to 50, to give the oportunity to adquire a powerfull item 

A mayor change can be you can select exactly what amount of level you whant a enchant, the cost in gems and levels express in tens. 1-10 level is 1 cost, 11-20 is 2 cost,....
Whit this changes (the bulet points) i think the enchanting table can be more balance in comparance with the librearians villagers and they trading