At some point in the future I thought it would be nice to get a Class 3 S.O.T, and maybe a class 2, and conventional manufactureing FFL aswell, since I'm completely discusted at the price of Transferable machineguns, and it's the only possible way to get non C&R NFA stuff in Michigan that I can think of, so what would be involved in getting one, and do I need a store front, or can I run it from home with a sighn saying "Hours by appointment only" posted, the purpose would mainly be for my own personel use, and online ordering, and catelogs for the business part of it, and how would I get Demo letters?....

$500 a year for SOT.
SteyrAug was seriously looking into it.
PM him.
He knows all.

First, the application for a standard class 01 FFL  has a question asking if the license would be used to build up your personal collection. Federal law specifically prohibits this practice, so I don't think it would be best to have your "main purpose" be for personal use.

Second, there is no federal requirement for a storefront. They only require that you observe all local laws regulating businesses, like zoning and such. So, one could run the business from their home if they were to follow all the local regulations.

Next, a Class 2 can do all the same things as a Class 3, in addition to building NFA weapons, so there isn't a need to have both. In order to get Demo letters you'd have to do some legwork.

Finally, in order to get the Class 2 (or 3) one must first have a standard FFL ($200 for 3 years/ $90 to renew) and then fill out the proper forms and submit them to ATF with the $500 yearly tax (covering July 1st through June 30th - this fee is not prorated. If you pay $500 in January that license is still only good until June 30th).