We sell them for 250€, but are currently out of stock.
We did a retrofit with Mach3 + CSMIO/IP-S so this works.
The CSMIO does not provide differential outputs according to RS422 (they use simple cmos drivers) so you are a bit limited on the max step frequency (i think it was around 150kHz).
That does sound appealing, would run me about 600 bucks less than buying the dinkiest simdrive servo/drive set.
Do they come in a housing or are they just bare PCBs?
includes housing (currently 3d printed, later sheet metal), heatsink, fan, connectors, support
excludes certification, guarantee, …
Naturally. Though I’m pretty sure you guys are not entirely disinclined to give support to a guy in his garage trying to assemble the thing… right? 
look at our gitter channel
If you are in NRW or near hannover or stuttgart we might even visit you.
You can save another 600 bucks with LinuxCNC + Mesa card (;
STMBL supports Mesa smartserial, so you get real communication between control and drive.