What would they have to promise the Bloc in order to get their support?
Before Harper went on his wild ride, saying every vote would be a confidence vote, and forcing the Liberals to vote for his budget, he was pushed into a corner by the Bloc, who presented a list of non-negotiable demands. With Bloc support conditional on that agenda, Harper decided to push the Liberals into a corner, and then run an election campaign. I believe that his latest electoral success lead him into hubris, and that's why he finds himself in the situation he's in now, and he's backpeddling furiously--but it may be too late.
I have been unable to find a published list of their demands on-line, but i recall that they wanted an extension of income trusts for ten years, Canadian ratification of the UN Declaration on the Rights of Indigenous Peoples, opposed dismantling the firearms registry and demanded Federal support for the Wheat Board. If anyone could come up with a list of the five demands they presented Harper, that could stand for a statement of the price for their participation in a coalition. The points i've mentioned above would not be offensive to the Liberals and the New Democrats, i believe.