Websearch for "DIY DMX to MIDI Interface".

You can build certain methods for as little as 10 dollars, depending upon what it is that you wish to control and how.

http://stevenbreuls.com/2013/05/diy-usb-dmx-dongle-interface-for-under-10/

http://www.musicianstechcentral.com/midihard.html

Of course, we can often find used stuff of this type for pennies on the dollar, as you have already. Keep yer eyes open. I often come across real savings when things like this are in need of repair, too, often the repair is rather simple, such as a power supply problem, perhaps one shorted rectifier, ye olde dried out electrolytic cap(s), etc. - very rare that the actual digital portion of the circuitry is the culprit.


--Mac