system
Given the following post, respond as if you're commenting on Reddit:
human
[Skyrim] Why do shopkeepers hate quality enchantments?

Why do shopkeepers give you less money for your enchanted goods, the higher your enchantment level is?
gpt
Risk and demand versus reward.

Sure the adventurer might want to sell the vendor a +9 Ogre Slaying Knife (+9 versus Trolls) but that's such a single purpose item, very few shoppers are going to want that.

It's the sort of thing that could be advertised across the realms... 'Jack the Smith in Wheretown has the perfect ogre weapon !' And cause all kinds of ruckus for the town (maybe the troll king has a problem with ogres and mutinies) and draw one or two heroes from far and wide... but how long will he really want to keep it in stock due to the former reason?

Not to mention laying out a large investment on a weapon that's going to sit in a display case as a curiosity until then...