[POWER RANGERS] Which are the most expensive produced seasons?

Hey guys!! Im curently watching the 4th PR DVD SET and while rewatching the Disney seasons, especially SPD and Mystic Force , the matter of the PR budget come to mind. I remember back in the day when I First saw those two seasons I was very impresed by the production and special effects, so this got me thinking. Disney seasons were very well produced and looked less cheaper than previous one. So does this mean that despite the fact that they moved the show to New Zeland and reducing the episode number did they kept a higher standard for the look of the show simply becuase they are Disney? And do we know which were the most expensive produced seasons from both Saban and Disney?