First, it is being reported that:
Among the teams with the 10 highest averages, only San Francisco ($3.8 million) had a losing record (76-85). Among clubs with the 12 lowest averages, the only one with a winning record was Toronto (87-75).
Based on this, can there really be any doubt that unequal payrolls among teams undermines the competitive balance of baseball? On average, money buys wins. It's that simple. So, as long as money is not balanced roughly equally among the teams, there will be some teams with a much better chance to win than some other teams.
The second thought is, how do we fix this? Revenue sharing helps. But I think what would also be good is to eliminate some of the inefficiences in the current system. For instance, the Yankees and Mets have a huge advantage because they are in the New York market. There are two teams sharing a market that is far more than twice as big as many other markets. I say add one or two more New York teams to the mix (not to mention Boston and other cities). If New York could sustain three teams long ago, they should certainly be able to do it now. And if MLB won't let this happen (which presumably they won't), then somebody should start a competing league. Perhaps the USLB?