Agreed, the shows are the best place to go.
I seem to do most of my business with Bob's Shooting Supplies out of Monroe, about 20 miles east of DSM. He has a small shop, but mostly works the shows. Transfer fee is $20 or $25, can't remember which. Have bought from Jack Smith. JLM is a petting zoo, pretty to look at but too expensive. Jacobson's in Story City is decent shop, but also on the high side. He is one of the few gunsmiths in the area tho. Does good work but is usually several weeks behind.
Been to Jim's once or twice. Has lots of stuff.
Ammo Bearer, Fin and Feather, and Scheel's, all in the Iowa City area are also good. Supposed to get a Scheels at the new mall in WDM, but that's at least a year away.
Still a few "basement bandits" out there but they are gitting fewer and fewer. Most are strictly word of mouth, friend to friend deals.