Craig,
If you can, search for some free audio blue book quotes. I used to have a link to pull this data for free, but lost the link.
It would allow you to get some kind of general idea what your speakers are worth - for 3 conditions: excellent, good and fair. This would guide you in setting your asking price. Keep in mind, in order to get the best price, there has to be a willing buyer. IMO, Craigslist (I'm sure no relation to you) has been a mixed area when I've sold stuff in the past. Some great connections ... some insults from people who wanted to offer me 50% or more off my asking price.
Best of luck.
