Ceramic bearings in your jockey wheels does not save a couple of watts. It doesn’t even save one watt.
The difference between Dura Ace stock steel bearings and top of the line ceramic jockey wheel bearings is on the order of 150 MILLIwatts. You read that correctly: 0.150 Watts saved. Not worth the money in my opinion.
Now, if you have a regular Shimano 105 rear derailleur and you want to replace the bushing pulley wheels with a quality steel bearing pulley wheel, that is WELL worth the money. That really can save you more than a watt. For less than $50. So go for it.
But, full ceramic in the jockey wheels? Not worth it. Save your money.