This article covers the main reason why we are still quite far from inexpensive AND quality consumer level machines for hundreds instead of tens of thousands of dollars: Intellectual Property and Patent Law.
Companies like 3D Systems and Stratasys have thrown millions into RnD and have patented many of their ideas. Though some of the patents do seem to be as reasonable as patenting the rectangle, while others make a little more sense, they all prevent outsiders from coming in and producing the same great machine for much less until the patents expire, which in some cases are as late as the mid 2020’s. In the meantime, expect the most affordable printers with any quality to cost thousands while Stratasys and 3D Systems make very high margins on equipment and “ink” that is not terribly expensive to produce, because they really have no incentive to lower their prices.
One serious competitor to the two giants is Formlabs and their $3200 dollar SLA machine. They created a system based on an expired 3D Systems patent, but patent law is so murkey they are being sued anyways for violating some other patent, the specifics of which I have been unable to locate.