ECI clamp if we can still find one is about $150 or so
BI clamp may be a little less, and it will not be a standard BI clamp
as the ECI boom does not have the flats machined @ the end of the boom
the clamp mouth is wider , the BI booms have flats (or square) machined on the boom clamp end
so the clamp mouth is narrower than the ECI clamp, the BI clamp is by far more beefy
than the ECI clamp
Dan T