The 01 FFL is for those who are in the business of dealing in firearms. It is not to be used to enhance your personal collection.
While the ATF has cut down considerabley on the number of "kitchen table" dealers over the past 10 years, you are not required to have a storefront to get a 01 FFL. This is a common misconception, but I know of too many people who have a 01 FFL and operate out of their home to believe it is true. It is easier to meet the ATF requirements if you have a storefront though.
The ATF does check to make sure that you are in compliance with all local zoning and business laws though. If you plan to operate out of your home, this may stop you from doing so, depending on your zoning and any local regs. You'll need to show zoning compliance, have the necessary business licenses, etc. If the zoning issue doesn't stop you there, the rest is not insurmountable.
The ATF also does do compliance inspections. When they look at your bound book you had better be able to show them a pattern of firearms sales to people outside of yourself and your immediate family. If they believe you are not actually "engaged in the business" of dealing in firearms, they will not renew your license.
So in, short, if you want to run a business dealing in firearms, a 01 FFL is appropriate. If you just want to save a little money on your own purchases, it is not appopriate.