Plausible theory on price changes for Rares

Well, of course, the biggest news today is the Stronghold of Player Safety, which is a great addition to the game. Definitely right step from Jagex. I can only applaud. The new Slugs quest was also quite good, I especially liked the "villagers luring" part and "creepy" puzzles.

But what I would like to feature today is an interesting an very plausible theory on price changes for Rares. Here it is in a nutshell (taken from ikraz55's post on the TruthScape forum):

Maybe Jagex hasn't purposefully frozen the price of party hats and sgs/ags/zgs. The prices decline based on number of offers, and it may simply take a very large number of sale offers to change the price. This is fine for cheap and easily obtained things like flatpacks and iron ores, but there aren't enough selling offers for some rares to change the price. This would be the same reason that chef's delight (m) goes down very rarely, even though I have been trying to sell 30 for a while. They prices change rarely, and by small amounts, but they DO change.

I was always wondering why would Jagex freeze party hats and godswords prices. Now this theory explains it. It also accounts for my overpriced kegs of chef's delight, which I now proudly place on the same level with phats and godswords.