I think you'll get the best price by listing here in the classified section, except the Sinar P3.
When looking for price points, users tend to over-grade their equipment. Be sure to read the keh.com grading guidelines. Pricing 15-30% below keh would be a good start, you can always lower things if it doesn't sell as fast as you'd like.
The value of your equipment is very much going to be determined by the lenses and accessories you don't list. For example, the RZ67 might only bring $250-350, but including a 'full set' of 6 lenses and other accessories could bring it over $1,500.