The IRS works the same way. Organizations are supposed to work the same way. I recently received a receipt for a donation as I attended a dinner. The receipt stated my total “donation” of $250 and the tax deductible portion of $195 since I received a meal that they valued at $55.
As for those who attend the HASC concert (nothing against HASC – just that their concert is one of the better known venues of entertainment in this genre of tzedaka giving), lets be realistic, how many people go to the “hasc concert” and how many people are attending a “hasc fundraising event”. I’m not blaming the organizers or the attendees, just saying lets not fool ourselves here. How many concert goers would give even $18 a year to support hasc if they didnt go to the concert.