For quite awhile now I have been thinking about this and I have come to the conclusion that this game's prices are ramping up because of the tourny scene.
The pressure to create new and improved flavor of the month armies has been forcing GW to churn out bigger and better things constantly.
A new codex is ALWAYS the flavor of the month, its not because its crazy over powered its because its new.
The competitive scene is not happy unless new trump cards are pushed into the system. If a model is broken in terms of power rules the answer is not to nerf it but to create something just as broken.
Well for as long as I have been playing this game GW refuses to try and balance all armies to the best of their ability. They instead create trump cards, So people have accepted that fact demand more trump cards. Also remember the players don't have the ability to put out an official FAQ.
To say its only tournament players that complain is complete hogwash. Everybody complains about something in the game whether it be a tournament player, or a casual player.
On the same point I would say tournament players would probably want more trump cards because they unlike casual players wind up playing against a lot of dirty power builds where as casual players avoid them.
The problem at least half the time is as soon as someone runs into an army that completely counters theirs they start crying and saying that the army is broken instead of just accepting the fact that some armies fair better then others against specific armies. People always want their army to be able to deal with everything the same which cant and frankly will never happen.
I think that GW has been taking steps to correct this issue with the releases of 6th edition but the damage was already done. They got a taste of what the Magic the Gathering style system can give a business. When you have massive sales to keep up with the new flavor of the month in a competitive system then you start to think in terms of how to maximize this aspect.
GW tried to step up to this demand with the Ard Boyz circuit but it backfired on them because they could not keep control of the product supply. Ebay and online sales skyrocketed because of the buy one month, pawn it off for the new flavor next month mentality.
Now they are back tracking on the matter but because of how the economy of it happened they also are taking more of a drain on the resources. They are pushing to get all of 6th out and have it be balanced but the backlash of 'watered' down codexes is losing them the people that were fueling the huge sales.
So instead of accepting this they have been upping the prices to try and keep themselves afloat in the hopes that the market will settle again.
Well most of this is your opinion and speculation so I cant really comment and I certainly cant say you are wrong. What I can say is GW is actually trying to control their inventory and require sales receipts in order to swap models to stop people from purchasing things off web stores or other stores at a discount and then go to their local GW and get full value in trade. This is also how they are hoping to stop people from trying to swap out old models for new ones.