The incentive idea is one aspect that makes nym stand out, but the thing I find particularly interesting about nym is it is a mixnet that eliminates size and timing patterns of data packets making all traffic look indistinguishable. This is not true for Tor afaik.
Discussion
You make a good point. Although since it is paid, you might have a little bit less usage from those who are extremely poor, just due to the fact that they won't be able to afford to buy whatever is needed for the incentive. That would probably be something that would need to be worked out if it has not been already. Like I'm imagining a person from like Pakistan or something trying to use it and being told they have to pay to use it.