Custom merchant beyond tedious, almost unmanageable

The image should quickly make everyone know what I am talking about...

• You cannot spot what in the list is the item you wish to remove or have already added ;
• I tried to sort the Spiritual Weapon Scroll (recipe) to place it with the other level 2 spell recipes... Pretty much impossible!  I had to get in the DM and talk to the merchant, count from the bottom to guess which one will be the correct scroll... and then exit to the DM campaign UI... but then tracking the sorting up/down is almost impossible. 
• The items in the "selection UI" are in some form of arbitrary order : not quite alphabetical, not quite by level... mostly sorted by type (scroll, poison, enchantment) with various exceptions mixed up.  
• Minor detail : Fireball and Fly somehow cost 100, while other level 3 scroll recipes cost 150. 

This is beyond tedious.

I am making a Headquarter space where characters can sell their loot and manage their gear before or after DM adventures, but it is taking me many hours more only because of this UI.  The default merchants do not do the job for many reasons; they don't even have the items to start with, but then there is also the question of buying/selling viability for DM campaigns.  A custom merchant is the solution, but...

I could have placed all the spell scroll recipes in a container, which would have been admitting defeat really (although maybe all characters should de facto know how to scribe their own spells if they have the Scribing proficiency).
I did place all level 1 scroll recipes in a container for free.