Looking at try 4 (since i'm guessing everyone understood the fight a bit better) bloodnova only generates 25 BP, which seems reasonable enough.
Your paladin tank took 96 hits with rune of blood active, thats 96 BP to saurfang and 2.4m HP healed, when, with appropriate tank switching that number should be closer to 0. Don't use the single tank strat.
You also chose to keep the marked victims alive, that generated an additional 219 BP on your last attempt. When letting them die would have negated that completely.
Total BP generated:
Rune of Blood: 96
Mark of Champion: 219
Boiling blood: 202 (this ones unavoidable)
Blood beasts: 45 (meh...in an ideal world this'd be 0 but 45's not going to kill you)
Thats a total of: 587 BP, so you almost hit a 6th mark
If you tank swap and let each of the Mark'd die this will reduce to 272 BP, only enough for 2 marks at the time you died. The only downside to letting the marks die is the 5% heal to saurfang, however that would only equate to 3.5m HP. Your single tank strat generated 2.4m HP to this really only leaves you with a 1.1m HP deficit to overcome.
Hope that helps.