I don't know how you could come to that conclusion. UFC guys have struggled against Pride guys and Pride guys have struggled against UFC guys. Pride is better in the HW division with Fedor, but aside from that, I would say they are relatively even with maybe even a slight edge to UFC.
Pride does pay more, but that is only because the fights are held in Japan and the Japanese are crazy about MMA. If you merged UFC and Pride and fought both in America and in Japan, it would be just as lucrative, if not more, than Pride is now.