How difficult it is, is dependant on your situtaton. You are required to have place of business with "SET" hours. The store front can be a room in your house with public access. Their intent is that you are actually engaged in a business, not jut ordering for yourself and frields.
You will have to get documentation from you local police acknowledging they know you are selling firearms. Can they veto your location... I'm not really sure when I looked at it I never got that far. You will also have to have safe storage for the guns which is a very vague statement but there are many options.
I looked at this mid year last year and had several long conversation with the local BATF agents (they are very helpful). Unfortunately my employer nixed me doing it. They said it would be detrimental to the banks image if the collector was an arms dealer.
Feel free to PM me if you want to draw on anything I learned.
