Tim,
Nice product you guys. If I may give you a little feedback. Having dabbled in the 3D printing world a little bit (not kickstarter) but something else. The industry has become very saturated. Now filament extruders are sort of a the "next big thing" in 3D printing space but I do know there are a few others out there so you competition is picking up. Now I take a look at your selling prices and 1500+$ for a filament printer is pretty much an exclusionary price point for something like this, meaning I'm willing to bet most people in the 3D printing world won't pay that much for one or would look to your competition for something less expensive, even if yours is vastly superior, which, by the looks of it, it is.
.
Two things I want to point out, you claim that it's the fault of the marketing, but I notice further down on your page it seems you've listed a whole bunch of tech magazines, I'm assuming they covered your project? So maybe that's telling you it's not ONLY the marketing afterall, it's a combination of price point and crowded space also. Another thing that leads me to that point is you'll notice you have quite a few donations at the lower pledge level, so basically that's people telling you, "well I like what you're doing, but I don't like it enough to buy one at your current price point". So to me, I would soak al this information up and learn from it.
You have a good product it looks like, if I were you, I'd research my pants off to try to find manufactures that can bring your costs down so you can lower the price point significantly. Maybe emphasis how your extruder is vastly different and superior to other, less expensive models out there, why am I paying 1500+$ for an extruder when I can get one from Joe X's campaign for 400$... and I would also look into putting more work into the marketing. If that doesn't work. Then put the idea on the bench and move onto the next thing.
hope this helps
J-