Right now the shop is pretty organized but is missing things and could have different menus in my opinion.
Menus>
Blocks, Redstone, Ores, Decorations, Extras, Potions, Food, dyes, enchants, mob loot, spawners, brewing, farming, tools, and saplings, so this could be lowered not by much but still
also i think almost all items should be sellable other than tools and armor
Mix potions and brewing that way page 2- of brewing is potions
Saplings and sweet berries should be put into farming
wool and meats should be in mob loot
add the ender chest
add spawn eggs into the spawner menu
add all colored block, glass terracotta, beds (all colors), glazed terracotta, and concrete/concrete powder