headsets (DC and ASA)

You will be more successful if you find a niche. Offer headseat brands that
no one else in the area has on hand - Denali, Sennheiser, Pilot Avionics,
Lightspeed, etc. There are wonderful headsets out there other than DC's,
and they usually cost less and fit better (or, at the very least different.)
I think it's important to really shop around for a headset that feels good,
but most people have only a limited selection of headsets that are available
to try on from their FBO. So, carry the brands that your competition
doesn't and you won't have to compete strictly on price and provide a good
service for your customers.

My $0.02

-Aviv