Eric, you are not making an apples to apples comparison. How many people find air for $900 to Europe in season? Did you include port charges and pre-cruise hotel in Seabourn's prices? Did you include net prices and shipboard credits provided?
Regent isn't for everyone. I don't use all the ship's excursions. But, I would never make a geralized statement saying that one is more expensive or less based on one example and a great airfare deal from a specific airport.
Yes, I am a Regent cheerleader. I have 160 nights in last eight years. Will, I always cruise with Regent; probably not. I like the product, I like the crew, I like the itineraries, I like the seven seas society benefits, and I still find that it is a great value. I will be on Silversea's Prince Albert II next January; my first chance to make a comparison. I have many friends who sail both Regent and Seabourn; they don't seem to have a problem sailing both lines; why do you?