According to http://forum.myphorum.de/read.php?f=8773&i=171984&t=150185 a guyed mast for carrying FM/TV-broadcasting antennas costs in the USA
US$ = 30825,35 - 149,870801034 * h + 4,07356741146 * h^2 (h in metres).
Has someone more detailed formulas, also for
- towers insulated against ground
- free standing-lattice towers
- concrete towers?

hmmm...