Volvo's international sales are booming, so they can pass along some savings to builders. Several builders' that have exclusive Merc packages have excess inventory of unsold boats, Merc is laying off employees left and right. Merc needs to re-coup where they can, and their priceing is one way to do it.
That is my 2 cents anyway.
While I understand what you are saying, it goes against all the laws of supply and demand. When there is excess inventory prices will ALWAYS go down. Consequently, when product is flying off the shelf, prices will remain high or even increase. You don't have to look any further than Auto Manufacturers to see this in action. Rebates are never offered on the high demand, like some of the Japanese Hybrids and the New Shelby Mustang. Remember when people were paying OVER the sticker price for a PT Cruiser?
On the other hand, look at the deals being given out to buyers for Ford/Chevy/Dodge Pick-up trucks. The rebates are huge. While these trucks are still among the best sellers, my point is about the demand vs. the supply. There a rows of leftover trucks (and Mercruisers) sitting on lots.
I think the difference in the price has to do with Brand Recognition. Ask 10 first-time boat shoppers which one they've heard of and most would certainly say Mercruiser. On the other hand, recently I've seen a survey (maybe it was on this forum) and the vast majority of CURRENT boaters prefer the Volvo-Penta line. I was a bit suprised by this. My guess is Mercruiser has been surprised too, hence the layoffs and poor pricing strategy. They felt their name could command a premium price. With first time buyers, this is likely true. But I believe that repeat buyers will not pay the premium since the surveys I have seen, along with folks I talk to, would often not pick the Mercruiser if it were priced the same as a Volvo-Penta.
You can also flip it around and say that Volvo-Penta is pricing their product lower in order to penetrate the market that years ago was completely dominated by Mercruiser. I suspect there will be some pricing adjustments in tne next few years. Mercruiser will come down, Volvo-Penta will go up.