Exp for enchanted books costs too much

Please reduce the required exp costs for an enchment book to be used with an armor/weapon/tool... i have an enchanted pair of diamond boots that have the following Fire Protection 4 Depth Strider 3 Feather Fall 4 Thorns 3 Soul Speed 3 Unbreaking 3 And i wanted to add mending, but it costs too much... so i made a new pair of boots and added mending with other enchants to another book with other enchantments and the book is now usless as it too "costs to much"... so please REMOVE the capped limit on merging items with enchtment books... this had been an issue ever since enchantments were new...