And if you build them yourself, they are even cheaper. None of them are difficult.
I prefer a quad for mobile hunting, as it doesn't stick up as high above the roof
for vertical polarization. I use #12 solid copper wire and bend it back into shape
when it encounters a tree branch.
Yagis are good for getting out on foot, either using tape measure elements (which
can be used with any yagi design) or some #14 wire stuck through a board.
The "offset" attenuator is just a crystal oscillator feeding a mixer through a pot,
with a couple connectors. Add a switch if you want to get fancy. For those
who prefer Glo-FETs you could use a 12AD4 or 955 Acorn tube in the oscillator
and run it off +12V. We used to make kits for the locals and the total parts
count was less than 20, including the connectors and switch.
Here is one version of many, though I'd separate the DC and RF on the mixer to
prevent spurious responses, and probably use a balanced mixer:
http://www.homingin.com/joek0ov/offatten.html