Party hats are discontinued. They were given to all player of Runescape Classic on Christmas, 2001. They were originally given crackers, and the crackers were then pulled on players, with one receiving a party hat and the other a random item (i.e. bucket, cowhide, etc...) Therefore, the number of players in 2001 is MUCH MUCH MUUUCCHH less than it is now. This makes party hats in scarce supply. With people quitting each day with them, they are getting more expensive daily. They are being depleted. Each day more and more disappear. So thats whats making them rise and whatnot. Prices started a while after christmas for around 20k a party hat, with Purple being the rarest, and blue being the most common. The duping glitch happened, which made purple party hats multiply more than anything, because they were rare. And blue party hats being common, they didnt get duped at all. This leads to the blue partyhat being 2b+ and purple partyhats only ~880m. I personally can remember buying my first party hat set in Mid-2002 for 150K. That would be similar to around 50m today, in my opinion. Hopefully I helped some! If you need anymore info, just ask. -Hugger