I thing CJ is spot on.
list together, with a separate price for each piece (ski/ski/trailer)
I still think Craigslist offers the best bang for the (no) buck.... you can't beat free ! and the traffic is heavy enough to get most reasonably priced items sold easily, just obviously beware of the paypal/cashiers check scammers, and expect a no show or 3, so I'd recommend that they meet you at home only, to avoid you driving to a ramp and waiting for somebody that doesn't show up. (I did that once, and now its at my house or not at all) you could always negotiate a price at home then go to the ramp for a test ride, don't let them say "we'll talk price after the ride" because in all likelyhood they plan on taking a ride then lowballing you, screw that... settle on a predetermined price first based on a successful test ride, before you commit to all that hassle.
And weird as it is, many buyers really just want to know that your agreeable to a test ride, but never actually take one, (obviously winter factors in there). But they will ask if your agreeable just to make sure your "legit" and not hiding something. I've sold a few ski's, quite a few but only ONE customer has actually taken a test ride (it was a 700 wave venture and he came back all jazzed up because of how "fast" it was.....) , and this is even crazier, not a single buyer has done a compression test to my recollection.
Its weird but true ! but most of my ski's were older 2 strokes, with a $1500-2000 price tag, not $7500 4 strokes, I suspect that more buyers would do the proper due diligence on a more expensive ski, but I've been surprised before
good luck with the sale !
(and ps.. don't discount the idea of parking them at a bank/shopping center, I have done that on several ski's,most of them acually, i've sold more than one that way, you also generally get a better price from a drive by.. since it is more of an impulse buy then)