Built a Seq V4L last year, not in a case but complete. 200 shipped in US. Also have a Quad II expander - add $50 if you want it as well. I bought more GM5 chips than I needed and have pcbs to go with them. $15 each shipped. I have 3 Gm5 chip/pcb combos available.
http://discourse.midibox.org/t/topic/17031
I also have a GORF midi sequencer for sale - $100 assembled.