Ahhh! My first thought after reading this was "that would only hold if you have a captive market". Then I realized Emotiva pretty much has a captive market (DUH!). If another company offered a decent 200Watt Amp for $600, I think Emotive would lose a lot of sales of across the UPA-200, XPA-3, and XPA2.
The point I was missing was that they essentially the only player in the market for value separates. Their toughest competition is a pair of outlaw 2200 monolocks for $674 (in most cases spending another $126 for the XPA-2 makes better sense).
As long as no one else offers competition, they don't have much incentive to add a two channel version of the XPA-3. Kind of a shame, I still think a lot of people who are upgrading by adding a separate amp wish the UPA-200 was more, but don't need or want to pay for an XPA-2.