Mending suggestion / alternative to villager nerf

Rather than attempting to weaken Mending by making it harder to get I propose two options that would balance it without making it impossible for more casual gamers to get.

1) change the mechanic entirely. Rather than mending allowing experience t0 repair the tool, change the enchant so that repairing a tool always costs one level per existing enchant level plus one level per material used, but **DOES NOT** change the previous work and **CAN NEVER** cause Too Expensive. For example, a Diamond sword with Smite V, Unbreaking III, Looting II, and Mending (Mending should be a Level 5 enchant) that requires 3 diamonds to repair would cost 5+3+3+5+3 = 19 levels and 3 diamonds to repair, but would never become too expensive and not add to the previous work total if you wanted to add for example Sweeping Edge after the sword had been repaired 4 times.

2) Change the villager mechanic so that they work more like the enchantment table. After you finish trading with them and close the interaction, assuming a trade has been made. they reset the available trade at that level for all levels traded. Further, the Librarian should only be able to trade appropriate level items at each level. Level 1 books at novice, 1-2 at apprentice, 2-3 at journeyman, 3-4 at expert and 4-5 at master. And yes, they should be able to trade books at all levels. Using this system (and considering Mending to be level 5) you could get Mending at any village, but only from Master villagers

Or both