Runescape Game Play

I have noticed that one of the messages of the week is that darts and knives are the fastest weapons on Runescape, they are correct stating this,  knives sell very quickly on the Grand Exchange that is why knives and bolts are the main smithers item (financially challenged players mainly) .

They may well be the fastest item but for xp they are pretty much useless, when I was training range I was told to use knives because they were quick xp, happy to try anything I took rune knives with me on my slayer tasks, I was advised to take bronze or Iron because I could just leave them and not bother picking them up saving time, I had my accumulator so used rune to hopefuly make it go quicker, it was great a double quick weapon but there was a snag, I couldnt hit anything, 0,0,0,0,14,0,12,0,0,18,0,0, the 0,s well out numbered even the low reds, so yes it was fast but you get xp for hits and I just wasnt getting any, it was bareable on things with little defence but as soon as you had a monster with the slightest defence they just couldnt penetrate.

This brings me on to a strange Grand Exchange phenomenon, the Grand Exchange moves in mysterious ways but I can not think of the reasoning or point of what follows, I have for years collected rune dart (p) from monster drops, mainly metal dragons, a couple of years ago I had a few k of them and decided I dont use them so I will put them on GE, they didnt sell, even at minimum they would not sell, for the last 2 years they have been on GE at minimum only taking them out to change the price to minimum again, the price has gone up and down by huge amount and still unable to sell, this is the chart for the last 180 days.

Every day I need to adjust my minimum price to stop it going to sleep on the GE, perhaps they are trying to generate some junk for junk trades, it escapes my why it is so artificially adjusted, rune darts (p+) had a similar peak in November.

I have millions worth of darts but just cant get at it,

WHY?