This article is from the Macintosh for sale FAQ, by Elliotte Rusty Harold firstname.lastname@example.org with numerous contributions by others.
LOCAL bulletin boards, both of the electronic and paper
varieties, are a far better medium for the sale of used hardware,
software, and other tangible quantities. Some Usenet sites and
local areas have local for sale newsgroups (e.g. nj.forsale
here in New Jersey) which are more appropriate for classified
advertising than netwide groups like comp.sys.mac.wanted. In
large cities and college towns you should reach just as many
potential buyers by advertising locally as by posting to the net.
Advertising locally gives both the seller and the buyer the BIG
advantage of being able to meet to test the system, verify that
what is being offered is in fact what is available, and avoiding
the hassle of shipping. The chance of being ripped off either
through non-payment or non-delivery is GREATLY reduced by
advertising and selling locally.