There are advantages in selling the Bulletin , more than just cost recovery if this is an issue. A financial transaction, however small, takes the acquisition of a Bulletin away from that of the usual array of conference handouts.
Sale can be time-consuming or awkward, however.
Some consumer opinion should be sought on approximate price. Another price consideration is a convenient unit of currency, for example the smallest note. Tokens or stamps could be sold in advance. This would enable the production size of each issue to be most finely regulated. See Case Study 8 on the Global Forum at Rio de Janeiro.