Scalping Boston Marathon Bibs?  Do they allow such a thing?  I'm more than slightly offended if they allow horse trading bibs when the majority of the running population is doing their damndest to qualify.  Not to mention all those who qualified and didn't make the cut.

Many charities have bibs available, of course there is a fundraising requirement.  You can check out groups like buildOn or search for other groups who are accepting applications.

http://www.buildon.org/boston-marathon/