They are surprisingly linked to their RWT value. Since the dollar value of GP has risen, the gold value of the santas are dropping to compensate. Virtually all rates have taken a hit in the past few months.
I seeeee, so what do you predict will happen to them in say.. 6 months? also, your post count is at 6,666
Damn, i missed 6666 and went clear to 6667 Now here's 6668! >_< Oh well, I'll try to catch it in the next 1099 posts. Anyway, the RWT trend for all rares is a steady increase. I would be surprised if they rose a lot in 6 months, but maybe by ~$5 or so. It's all hard to say, and I wouldn't even want to guess the GP value. If gold goes up to $2/m, all rares will probably crash.
Bots have a huge impact on economy. If someone is raking in millions of GP/day, and if alot of people are doing that, there will be so much money floating around, that GP will go down in value.
Oh ye sorry, I was too busy reading the rest of the thread It's quite hard to predict Runescape rare value rise/drop. So in all honesty there is no fool proof way of knowing.