This fest I've noticed a distinct lack of certain essences to go around and an over abundance of others, and the prices for the fewer ones have been ridiculously raised. This made me wonder if it would be possible to have an NPC vendor (one that lets you trade one essence for another of the same type but a different species) that lasts for the duration of the fest. It would be something like this:

*You can only trade regular essences for regular essences, enhanced for enhanced, and mythical for mythical

*Within the regular/enhanced/mythical categories you can only trade fabled for fabled and non-fabled for non-fabled

The only problem I see with this is people over running the market with low priced essences.

Let's say I get a regular bulbori essence before this starts for 30k. Now that fest has started, I can exchange it until I get an expensive essence. Now the market is swamped with popular essences, and have lost value.

Maybe if you could only exchange every 8 hours, you wouldn't have this problem as people wouldn't be just throwing them in the machine repeatedly.

I'm not sure I agree with this - supply and demand exists for a reason, the essences going for higher prices are more highly sought after. They're not falsely inflated - people pay their asking prices. I would support this if essences were something that were impossible (or far more difficult) to come across but as they can be found for free just from nurturing I do think the "luck of the draw" should remain - if people want a specific species of essence they could just nurture that species, but the essence shouldn't just be handed to them. I'm not sure a move that would deliberately cause the price of essences to crash is a good move on the gold front, the nurturing front or the diamond front when it comes to people buying essences from the diamond shop - there'd be no point if you could just swap any cheap essence for what you're looking for.

I think this is a nice idea but I think it would sabotage the market and make the game far easier - I much prefer that people should sell the essences and items they do have and save up for a more expensive essence, or just go and manually nurture for it, to preserve the prices of essences.