Agree with the 'Sale Pending'-thing dissent; in fact, if your ad becomes stale after a couple of viewing weeks, you might want to add something along the lines of 'Still Available' to your title copy, so people won't assume that it's already gone or something.
I think a lot of what moves and what doesn't, particularly when it comes to digital and also cables, has to do with what has 'buzz' - what's perceived as being hot or not at the moment. I don't think price, except for something way out of the ballpark, will have too much to do with response, since people will still inquire with lower offers if you've only set it a little too high. Probably the worst thing for a quick sale is if your piece was the hottest thing going in its catagory and price range just a couple of years ago, and the resale market is now substantially saturated and depreciated. The other killer can be if the 'next big advancement' has just come along to render your gear now 'out of date', at least until the latest craze blows over.
Recently, a currently-manufactured, well-known and reviewed DAC I was selling took the whole 30 days of the ad to move, while just half a year ago when I bought it myself on the 'Gon, the unit at the same price had multiple quick responses with offers to buy arriving after mine, according to the first seller (whom I trust). Just persevere and you will probably be rewarded, but keep in mind that it is common for people generally to slow down a bit on making discretionary purchases for themselves as the gift-giving holidays approach. Also, I think it can be important as to when your gear is listed on the 'New Today' page before getting shuttled off to the catagorized listings; I began that ad I refered to on the Friday of a 3-day holiday weekend, not a smart idea in retrospect. I suspect that the best initial response is generated by ads posted at the beginning of the work week.