Parts List:  Two 'Cross Wind Indicators'
     Home Depot or Hardware Store:
1.  5 ft. of ¼ in Aluminum Channel
2.  6 in. of 3/8 in Aluminum Channel
3.  6 in. of 3/8 in Aluminum Rod
4.  Three  36" of 1/8 in Steel Rod
5.  6 in. of 5/16 Steel Rod
6.  12 in. of No. 16 steel wire.
7.  Brass Fan or Drape Pull Pendent.
8.  Misc nuts, bolts, screws, C clips.
     Alum. pop rivets if you have gun.
9.  Two Pieces of Cora-plast 24 - 25" x 10"
      holes running across the 10"
      I get mine from Sign Stores scraps.

     Auto Parts Store:
10.  Two 1/8" brass Tube Union. (Brass-Tite #43001)
       (Buy 3 good chance of messing one up)

     Large Appliance or Furniture Stores:
11.  Two Blocks of Styrofoam 4" x 6" x 2"

I am guessing that if you have to buy all the bits and pieces it will cost you around $25 to build two flags.   The stands would be extra.