At the time they went to the donation arrangement, I thought they were making a big mistake. The advantage they had, and gave away, was that the R&F paid for the mags up front. What they did with them (place them for free, place them for cost, pile them up in the closet) didn't matter to the WTBS. They would have been money ahead to pay the taxes and be done with it.
I think part of the decision was that they didn't think the locals could handle figuring out all the taxes. A subscription service maintained at HQ would be relatively easy to administer, as all the money would come into one place and the staff their could handle it.