I can definitely see myself slowing down. Some of its rising costs, but also a lack of space. With my OT Star Wars wants pretty much taken care of after Leia, ROTJ Luke and maybe Tarkin, it'll be down mostly to new SW releases and the occasional Marvel hero when they introduce new ones.
It's an interesting thing - once you've gotten HT-quality figs of all the characters you want to display, what then?
I'm getting close to all the characters I want (have had to make a bunch though like Bespin Guard, Ree Yees, Ugnaught etc.) but am also almost out of space.
Waiting on Leia Hoth, Han Besp and Luke Jedi, then... hmm... no more Freaks, no more anticipating new 1/6 releases?