Build your own dual-extractor 3D printer with the Geeetech i3 Pro C Kit ($340).
Once assembled, the i3 Pro C prints with ABS and PLA and is a great low-cost solution for builds that don’t require high precision. It has a layer height resolution of 0.1 mm – 0.3 mm, a positioning precision of 0.1-0.3mm on Z axis, and a maximum build envelope is 200 x200x180mm.
The dual extruder can print a single one- or two-color object or two objects of different colors in one print job. You can also print one single-color object, as with other single-extruder 3D printers. Or you can use one extruder for infill or support. (Color mixing, however, is not supported.)