Its just one of the cause.
I got a couple of conclusions too,
1.) People(sellers) who pretend to be a random guy on trade and post, "Wtb ms 1m" and if u pm them they will tell u "I already bought one" tho they really didn't, it was just to show to children(buyer&seller) that that price is exact and fair. Therefor other sellers adapt the price (coz why not? the more the better.)
2.)Some people also do retails which increases 20-50% of price he capital. Most of them do the trick(#1) to manipulate the price.
Tho I am not against it neither is pro to it, for I fully understand why staffs/devs has no right to control the MS price. But if MS price wreck is the reason that # of players online drops, I'm afraid im going to support the protest of these children #500kms