You can probably squeak by with 2" for halfstock and late fullstock, but it will be a limitation in terms of earlier rifles or even later ones with castoff. With planed dimensional lumber, however, you are paying for a lot of finish work that you don't need.
The vendors are quite reasonable especially on halfstock length blanks, in my experience. Is Friendship an option? You can pick up a lot of blanks there and save on shipping. Even better if you call and have them bring what you want. Likewise, people here with blanks often go to shows, and they don't often mind meeting you there.