That's a pretty fair price. When I made mine, I figured a guy should have to charge around $350-$400USD to make it worthwhile. Maybe that's just because I'm slower and less efficient than you are at this task. I'm still hoping someone here in the US will give it a go and maybe make some for others. I'm still too busy trying to come up with something I can actually make a living at to be available to make these right now. We'll be watching for a ride report from JeffGill when he gets it sorted and run a few miles.
BTW, my rear shock length from eye to eye is set at around 12.5" or 31.75cm long. If Jeff has an adjustable ride height aftermarket shock he should try this height in the rear as a good starting point. Actually, with the thicker .125 material up front, adding 1/32" to this dimension would actually put the front and rear at the same relative height as mine which seems to work well. I think the stock rear shock height is slightly shoter so it should work fine too with a slightly lower height up front.
Thanks again for helping out a fellow BMW enthusiast with a big project like this