The big question is, does your Warden believe there is such a thing as a price too high to pay for ending the Blight? Granted, the DR is no obstacle to that goal but it is also gambling when the decision is made.
What's funny is that this is the motto Duncan passes on to us and of which Alistair reminds our Warden constantly. Even a darkspawn knows its meaning, better than some Wardens, and has taken action to combat the Blight using what few resources he had available (the Architect in DA: Awakening, not in The Calling).
And yet, I've seen people comment on Youtube absurdities such as: "My Warden died a hero and a good Warden by making the Ultimate Sacrifice rather than taking the easy way out by performing the DR."
But wait. Doesn't the DR end the Blight with the advantage of sparing a Warden's life, so that he/she may continue to fight against the Blight, as is his/her sworn duty? So ending the Blight through the means of killing one Warden is more dutiful than sparing a Warden so that he may train others in the future and continue to serve humanity? Why? Because it's "the traditional way"? Because tradition is noble?
Only if it's the tradition of ignorance. The Archdemon is a magical creature. No one alive today knows how that magic works. The only people who know about such magic are Morrigan and Flemeth. The Wardens know NOTHING about it, so they came up with an imperfect solution, an improvisation, which uses forbidden magic: blood magic. We perform a blood rite willingly, an act that goes contrary to everything we uphold as righteous because it's "a noble sacrifice".
So doing another blood ritual later which is actually based on accurate knowledge about the magic behind the origin of an Archdemon is dirty, is wrong? It's not dutiful because you get to live? Even though the Wardens have been fighting that evil in the wrong way all along due to their deep-seated ignorance about the fundamentals behind how the magic behind the Blight and the Archdemon works?
In the end, what's funny is that no ultimate sacrifice is required at all. That'swhat the game is telling you. That's what the only people who are qualified at all to tell what's true from what's false regarding the taint, the Blight and Archdemons tell the players in the game. And yet some obviously very virtuous people completely missed the point and stubbornly chose to ignore such vital information, simply because it would look bad if my Warden didn't die, didn't do what was expected, even though it's a mistake that's been perpetrated for centuries by every Warden that's ever lived...while bashing other players who believe there's nothing morally wrong in doing the DR, much less of selfish at all.
The DR is simply the right solution for the problem. Dying is not required. In the end, every Warden that made the Ultimate Sacrifice died in vain.