I really like Robert at RK Gunsmithing, he charges $25.00 a transfer but after 5 transfers he lowers it to $20.00, he's a nice guy, fast and convenient since it seems most FFLs have him on file and he doesn't mind doing transfers. It bugs me when I do a transfer at places and it's a hard sell to buy ammo or they comment that maybe next time you should buy a gun from them instead.
My friend swears by Iguns http://iguns.pro/ They don't list transfer costs on their website but he says it's about half what RK charges and since it's out of his home his hours are very flexible. They advertise as being "Female Friendly"
I've used Hawktech before when I lived closer to Meridian but now I'm deeper in Nampa I don't but they were good as well. I've also used Hawktech for 2 NFA purchases and they have been great for those.