No, I don't think money is everything. I think consistency and cohesion is everything.
Sure, some of the 'plastic' clubs are thriving relatively compared to their previous obscurity, however, the winners are always the ones who have maintained their squad integrity.
Prior to their most recent Champions League finals victory, Bayer Munich has had the same team for the past 3-4 years. They've consistently been in semi's of the CL as well.
Barcelona, spends money because they can, but the fact is that their core has remained intact for many years now and it has proven them success.
In the Premier league, who wins the title last year? A team, that most of us would agree is NOT at their peak right, but because of their consistency in the squad(obviously the addition of Van Persie is a huge difference maker), they win the title.
As far as disparity goes, yeah I think the fact that clubs like PSG and Dortmund are showing their faces is a great sign, as well as Munich who have been knocking on the door for several years. If you look at the semi-finals of the past three Champions League matches, you'll be surprised of the names you see there. It's tough to judge past that because the underdog seems to lose in the Semi's, to the consistency of some of these more experienced/better teams .
I don't know about you,but I absolutely love the fact that neither Barca nor Real won the Champions League this year, nor last. I call that disparity when two Bundesliga team are playing for the highest honor the sport has to offer on a club level.