Quincy Hill Townhouse Association

There are 2 skylight companies in our monthly newsletter: AIA Plastics and Skylihgt Specialists.  I have contacted both about pricing for the entire curb mount unit (we didn't want to just replace the plexiglass).  AIA wants 285.00 per skylight and Skylight Specialists want around 2800.00 for the total job of ordering the skylights and installing them.  My husband and I had an installer measure and take a look at the condition of them and nothing but just the unit needs replacing (the curb and the roofing/flashing are ok).  I know Home Depot replaces them around 139.00 to 179.00 per unit but are having trouble finding a close measurement.
 
  Does anyone know who else can manufacture these curb mount skylights for us for around what Home Depot would charge?