I have definitely cooled my jets since starting on this hobby 5 years ago. But I attribute that to several different things.
Firstly, there was that initial high of starting out and getting as many figures as I could. I started with Sideshow Star Wars and Indy, and there were plenty to be had in 2008. In 2008-2009 I averaged to about 1 a month. I know that's nothing compared to some people on this board, but it was a lot for me. But that impulse to buy everything that looked awesome was part of the whole "honeymoon phase" of the hobby and it was only a matter of time til that stopped.
Secondly: the price. 5 years ago the first few figures I got were only about $65 (ANH Han was the first figure) and that was a huge amount for me at the time. I never paid more than maybe $15 for a single figure, so $65 was quite a psychological hurdle to clear. And I had Indy on pre-order for $90! It was very difficult to justify these extravagant purchases back then. But somehow I did. Since then prices have jumped significantly, which has made it much easier to say "no" to certain figures.
Which now brings me to my last point. I bought a couple of "filler" figures for superficial reasons. Those taught me to think thoroughly of my purchase before I commit to buying. That's really the main reason I've slowed my purchasing: I now buy only what I absolutely love. It's a difficult process, but I'm extremely happy with the focused collection I'm building.
There are still plenty of figures that I'm waiting for anyone to make, so I don't feel like I'm done with the hobby. I still get great pleasure from looking at my collection and am still awestruck at their amazing detail and complexities. But for the past three years I've only bought between 2 (last year) and 6 per year. So far this year I've only gotten Tamashii Threepio and have HT Wolverine coming next month. I'm also hoping to get the Brothers Production Blade Runner Deckard as well. But I think that will be it for 2013. I doubt anything else is yet to be announced this year that will also be released by December. And the only figures that interest me for next year is Iron Man Mark 42, Sleepy Hollow Depp, Prometheus, Sideshow's Vader 2.0, and Grievous (if he ever gets put up for pre-sale), all of which are still big maybes for me. The only sure purchase for next year so far is the Tamashii R2.
So maybe it has peaked for me and I'm living out the golden years of 1/6 collecting. I'd like to think I've matured to the age that I know how to play the game. I'll close with a quote from a great poet who once said:
You got to know when to hold 'em, know when to fold 'em,
Know when to walk away and know when to run.