Besides Martin, I don't know of anyone else who does it as a trade.
Easiest way would be to put it together yourself. You'd just need to buy an SR60i ($80), the TX drivers ($130), L-Cush pads ($20), and commission a set of wood cups from either Martin or Jin at Turbulent Labs once he starts making them again (~$150) - http://turbulentlabs.com/classic-vibro/
So that's a total of...around $350-400. Cheaper if you can pick up a second-hand SR60i, since all you'd be using from it is the headband / gimbals and its cable. And even cheaper yet if you want to forego the wood cups and just use the SR60i plastic housing, but that's more tricky and not easily done cleanly.
But with wood-cups, it's a simple matter of soldering the cable, seating the drivers (with either some thin foam strips or with thinly cut strips of electrical tape), and you're good to go. This is what I did, and I am not personally comfortable with DIY, so that should tell you how relatively easy it is.