I prefer BM'3 for the performance characteristics in terms of velocity, cleanliness, ignition and felt recoil. Not price.
The price is higher than everything else at this point.
If cost alone was my highest priority, I would not be using BM'3.
For that matter, I would not have several things that I presently have if cost was primary consideration.

According to BM'3, the BM'3 ignition threshold is in the 3-400 degree range, thus making it a wonderful powder for flint and percussion ML's.
Shot BM'3 in my older T/C hawken perc. last night in 70gr loads. Shoots fantastic! 20 shots and each one with a perfect ignition.

Cleanup is a truly a breeze.

I think that pioneer produces a fine product. I just prefer the Black Mag'3 over anything else.