Monoprice drops the price of a dual extrusion 3D printer to $700

No they actual manufacturer a lot of what they sell. You should listen to the NPR Planet Money episode it was really enlightening. I starting buying from them after I heard it. I also just thought they bought and sold sub par parts.

I've been buying their stuff for years and am very happy with it. The only time I had an issue with something they were happy to exchange it.

I've never had a bad product from Monoprice, including the USB cables I've bought.

The MicroUSB cables I get from them are fine, they just stop working after about a year. I stock up occasionally because I can buy a ton of them for cheap. But a friend of mine showed me these http://smile.amazon.com/Salsar-Colorful-Braided-Charger-Sams... and she says they haven't given her any trouble.

While I'm leery of buying anything that requires a lot of "engineering" or "design" from them, I've been quite happy with the cables and simple accessories like memory card readers I've gotten from them. I've been studying cables and connectors for a long time, and have had loads of my own custom cables and connectors manufactured in China. While I haven't done an analysis on the connectors they use, I recognize that their cables are made from high quality cable stock - usually from Copartner, which I regard very highly and believe to be the top shelf of the cable stock that you can get from China. Their mains power cables are very nice too, and they stock enough variants that my spec is usually met from their stock (for instance, 14 or 16AWG, right angles, 10 feet) without having to special order.

I even have Monoprice supply some of the commodity accessory cables that I include in various bits of kit that I sell, such as plain serial cables. I thought it would reflect badly on me when they started molding their name into the cable ends, but so far it seems that nobody's been unhappy.

They could lose their HDMI and USB licenses if they did.

Yeah, HDMI cables are a really bad example. Even with the monitor example it sounds like a lot of the price difference had to do with reducing the markup. I always assumed that this was monoprice's strategy, find items being sold with huge markups (e.g. HDMI and audio cables), and reduce the markup. I would be interested in hearing/reading more about the other ways they reduce costs which they talked about briefly (re-engineering to reduce production costs).

Make your own extruder holder (it's usually the first thing that gets designed) and pick one that is easy to unclog.

You'll eventually tune it to perfection.

That's my experience anyway.

Currently I'm loving the bondtech extruder and the E3D V6 hot end combination. Lots of control an very reliable in a wide variety of filament / control issues. Building that as a 'direct drive dual extruder' on this platform might be challenging given the available space but you could probably get it to work in a bowden configuration with the hot ends on the print head and the extruders attached to the back of the case next to the spools.

For electronics there is currently a big debate over the Replicape/Smoothieboard type tradeoffs. All serious folks have dumped the AVR/Arduino stuff in favor of either ARM Cortex-M stuff or the Beaglebone Black (like a RasPi but with more I/O). Most folks prefer the higher power 8825 stepper motor drivers over the older 4498 versions. There is a challenge there however, that if you're trying to run your motors that hot you are probably over driving your printer. I've currently got a CRAMPS board with a Beaglebone Black as a controller in my 'new' build, and I continue to print parts as needed on my Replicator Dual (which was the last fully opensource printer Makerbot made).

Would it be easy to run the heat bed from another, smaller power supply, or is that more complicated/expensive than it sounds?