Okay, so I had to re-do this because the Sonics becoming the Thunder totally screwed up the chart for several teams (see comments below). But I also took the liberty of adding in a win% column. I took out the 11-12 season from the payroll calculation because it didn't really belong.
Without further ado, I give you... the Chart of Destiny:
With the new and improved chart, you'll notice the Spurs and Wolves are at the top and bottom of the Win% list, and as John R points out in his comment below, they aren't extremes on the Revenue list. But I think these are perfect examples of management outweighing spending power. The Spurs are a nearly perfectly managed team, while the Wolves are the exact opposite. The Spurs are making money and winning, while the Wolves are losing money and losing. But if you go to the 2nd best and 2nd worst teams, the Mavs and the Clips, it's a more typical story that I think is more telling of the overall picture. The Mavs have a ton of money, the Mavs spend a ton of money, and the Mavs win. The Clippers don't have much money, the Clippers don't spend much money, and the Clippers lose.
As I said, I think this is the overall trend, so to first show the correlation between Revenue and Payroll, I made a scatter chart by sorting by Revenue, and then charting Payroll amounts. Revenue drops as you go from left to right:
It's not hugely pronounced, but if you have more money, you usually spend more on payroll. The Magic stick out as spending a lot for a poor team.
But the real question here is, do you win more by spending a lot? Not surprisingly, when I sorted by Win% and charted Payroll, it looked awfully familiar:
Obviously, the Knicks are a mismanaged outlier, spending money at will and getting no results at all. Overall, though, it seems that spending has a positive correlation with winning. Obviously it's not the only factor, but this would indicate that there could be some competitive imbalances related to how much money a team spends.