$4,000?!?! You're joking right?
Home Depot:
Enerflex 24 in. x 4 ft. Radiant Barrier - 50 per Contractor Box $190
Enerflex 4 ft. x 250 ft. Radiant Barrier Insulation Roll $250
They say you only need heavy duty scissors and staple gun to install.
http://www.homedepot.com/Building-Ma...0053&langId=-1
http://www.ufpi.com/product/enerflex/index.htm
Might want to rethink those numbers....