Will Thompson wrote:

Just about all of the major (USA) pilot shops on the web use a "minimum
advertised price" for headsets. ...
So why is this? Manufacturers *cannot* set actual selling prices, per
federal law (Sherman Act and related) so it is strange that they try to
impose this barrier. .

At any rate it is just a hassle for the consumer becaues it
intentionally makes it difficult to find the best price. You would think
the manufacturer wouldn't mind the end seller selling for the best
possible price to get more sales. UNLESS of course the manufacturer
secretly sells to different dealers at different prices.....

I've done a lot of business on the web, and it is both weird and
annoying that aviation .headsets operate differently than everything
else.

It's certainly not restricted to aviation headsets. For one example this
is very common for GPS receivers. Look at the prices at www.tvnav.com -
for many of the Garmin receivers it says to click to send email for
price. Clicking actually opens your email with the price already listed.

As to the rationale, I believe it is to help the small volume retailers
who cannot compete on price with many of the mail and internet ordering
sites or even with the bigger brick-and-mortar retailers. If the prices
were widely advertised it would become even more apparent how much more
the small stores are frequently charging. But the small stores are often
the ones where customers get a chance to see and play with the products.
And probably many of the customers who try on a headset or check out a
GPS at a small retailer end up buying from one of the cheaper mailorder
or internet shops.
If Garmin (or Lightspeed, etc.) didn't help out the smaller dealers
with a MAP policy, many would stop carrying these products and it would
hurt the overall sales of the products since they wouldn't be as accessible
to potential customers who want to 'try before they buy'.