Headsets: "Minimum Advertised Price"

Just about all of the major (USA) pilot shops on the web use a "minimum
advertised price" for headsets. The actual price for a popular headset,
such as Lightspeed or David Clark are not readily available on the
website. Instead you only find out the real price after actually
ordering or requesting and waiting for an email. The shops claim the
manufacturers require this, and they can't advertise a price below the
"minimum adv. price" which is usually somewhat lower than the MSRP or
list price.

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.