Another already explained it isn't a rip off so I'll explain the rest.
The low level 51 pink market caters to people who have a ton of ingame money to spend and want to have as painless as possible leveling experience from 51 to 55/56. They tend to vary from item to item, but while they are generally weaker than level 50 sets, they are somehow still cheaper than both level 50 set items and level 55 set items. For some people it's saving money because they can't afford level 50 sets, and for some people it's about "pinping out:" You wouldn't believe how slow the "last couple of levels" can feel without elixirs to somebody who just wants a capped character. On top of that, a low level pink can be put back into circulation immediately at 55, as opposed to level 55 ones which only get removed from the market because people want to wear them at the current endgame.
Oh, and while level 53 and 55 Brown/Purple items are 99% worthless, level 51 versions are also hot because they have the dame stats as their higher level counterparts for only slightly less armor/damage.
So yea, it isn't just for dual speccing, but that is one use.
I hope you understand now Physio.

Oh, and locked farmers have been on the rise lately from what I've seen. STS really should implement deaths not counting while locked, too. If kills counting while locked is stupid, deaths counting while locked is moronic.
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