Radio Shack is having a clearance sale on 5 ft. and 10 ft. steel
antenna masts:

These are stackable, but need to be bracketed to the house, and guyed. 
But, they make great supports for the ends of dipoles if, like mine, 
your trees are all in the wrong place.

The 5 ft mast is catalog number 15-862, and is
4.97 + tax.


The 10 ft mast is $6.97.

The part number for this one is 15-863.