Wellew, I disagree about firearms being maked up 10 percent. I regularly read shotgun news and attend guns shows as well as visiting retail shop regularly.
Guns at show and at retail sell for way more than shotgun news advertised prices. I'm guessing that ffl's often do better than advertised prices as well.
Like any business the goal is to buys right and sell right.
One example in shotgun news is a Siaga 308 that KY Imports has advertised for $239.00. I saw 2 of these sell at a gun show for $329.00.
I understand that the show seller has costs as well, table, tranportation, time, maybe a helper at the show, but there is money to be made if you do it correctly.