We might be able to ban paid per signature model, but not pay outright.
My point (here and otherwise) is that we can't create more limits to the initiative process and expect the process to improve. Creating higher hurdles to participation will only decrease participation, and increase the advantage wealthy folks have in using the system:
More regulation just means that initiative proponents will just spend more money to overcome these hurdles. The loser in this scenario is the average citizen. They do not have the resources to overcome these hurdles and therefore are locked out of the process. If legislators are concerned about wealthy individuals and special interest being the only ones using the process, then they should make the process more accessible to those individuals without access to large sums of money.