Sources for RSIC or Mason clips?

[MightyM]

I'm looking for sources (online or Chicago area) for RSIC or Mason isolating clips. The only source I've found so far is:
www.acousticalsurfaces.com
which has: RSIC DC04 for $6.40 ea, and RSIC CWB for $10.05 ea.

I was hoping to find a cheaper source. $10 per clip seems crazy expensive for something that costs pennies to manufacture.

I did find one local RSIC distributor (allieddrywall.com), but they only carry the RSIC-1 clip.

Thanks in advance - Mark