What are some of the better maps to run for currency?

I have been running burial chambers for about 300maps it is fine got 2 doctor cards my goal this league is finally obtain a headhunter so 2/8 of a headhunter is mine.
I just wonder is that the most efficient way to go about getting headhunter or would doing another map that has more common good cards. (Feels like burial chambers has less mobs than other maps too.)