Gather round, ladies and gentlemen. I've seen a few people come close to the right idea, but no one is thinking about the item that is about to go parabolic.
Jugs of Wine.
Previously, the Jugs of Wine had a few niche uses such as low level non melee training food and noted food at far away locations like Blackjacking. Since they had little to no use, the price was suppressed because creating the Jugs of Wine is one of the fastest Cooking training methods available, therefore had a supply that massively outgrew it's demand.
With Varlamore Pt 1's release, we received the Libation Pool Prayer training method. This created a use for the Jugs of Wine tied to a skilling method, which this item had never seen. Now the consumption of Wines has near infinitely increased due to going from off case uses to a consumable skill training method.
The Libation Pool allows players to add a lot of AFK time to their Prayer training, while also being more cost efficient GP/XP than Gilded Altar AND more afk/safe than Wildy Altar. I've also heard rumors that players have been comparing mining stars to mining the Bone Shards from the Calcium deposits, saying XP/H is similar. This means that players who want to train prayer will also have the option of training mining while getting supplies, again all afk.
Bone shards themselves enter the game in quite a few ways, definitely pushed by Jagex for players to interact with their new content. You can mine them, break down any type of bone for them, even are dropped from the new Perilous Moons Bosses. Jagex is incentivized to have players interact with the new content on Varlamore, either by adding additional methods of obtaining Bone Shards through P2 and P3, or even increasing reasons for more people to Defeat the Perilous Moons Bosses.
Those are the reasons that the Jugs of Wine will go up to around 30gp-40gp ea naturally, because of the limited number that are currently being added to the market each day. Last weekend, we had the highest consecutive volume days. If there is a catalyst, we could see numbers as high as 120ea-150ea. I can think of two very realistic catalysts and one that would take some divine reckoning.
Jagex adds new prayers to the game - This one seems the most likely. We've had multiple blogs and polls related to adding new prayers and it's something that the players really want and especially if they add more prayers at or above 85 because then every player that has 77 prayer will have to double their current XP, and everyone at 70 prayer will have to quadruple their XP. A lot of the players will have low bank values so something cost effective and AFK was made for them.
Jagex Buffs some point of the process - This could include making more Bone Shards available, to buffing Perilous Moons drops, introduce an item that has the ability to store XXXX amount of Libation Pool charges to bless bones and wines away from the altar, a dropped item that stacks with the Prayer Outfit that saves an additional X% of Bone Shards Maybe as player developed content to the new Mountain Boss. Anything to make you have more Bone Shards to use and a reason to buy/make more Wine. Again, Jagex is incentivized to make sure their Varlamore content hits with the recent blunders with Hunter's Guild and the Wildy Pirates misses.
Jagex increases the Jug of Wine buy limit due to new demand OR decrease the buy limits on Grapes and Jugs of Water, killing profit from bot farms - New demand fueled by their newest content means it's high time that we can enjoy new ways to play the game and to make sure you can play the game as long as possible, buy more wines for more afk time! Honestly, 6k on that item does feel really low or make the players not able to buy so many materials for cooking to decrease the supply, increasing the price and pulling the price of Jugs of Wine with it.
Volume has been steadily increasing but any time there is a spike in buy volume, the price skyrockets and takes days to start to come down while the times the supply is spiking it recovers to the same prices within hours. Check the charts yourselves.
People are right to invest in prayer XP, but you can't forget about it's component too. It's an opportunity that so many people are sleeping on. If you wanna be early and stack the odds in your favor, go ahead and do your own DD.
TL;DR
Wine had no use before, Wine have use now. Wine = Great GP/XP and AFK. No Wine soon, buy Wine before gone.