On CL, wording of your ad is REALLY important.
I just sold a motorcycle that I had posted 4 times, and it didn't move until I changed the wording (and dropped the price a tad).
They'll go, just make sure you emphasize the custom aspect of the guitar, and that it's a Buck Dharma sig model. Build up the exclusivity of the instrument.
The Blackheart is a popular amph these days, and should sell quickly at that price.