That depends on how often you make biscuits. I don't honestly see any reason not to buy self-rising flour for that. However, if you don't make biscuits often--I don't--you might not see any reason to buy it at all, since you can make biscuits with regular flour and leavening.
To research this, I made a batch of cookies today using self-rising flour. After all, on the label it says prominently, "Great for recipes!" So I thought, well, why not?
I decided to make Peanut Butter Cookies, an old standby. They have very few ingredients, especially if you go with the self-rising flour and don't need leavening. I used the recipe from the authoritative Joys of Cooking cookbook that I treasure over the years.
I also used Laura Scudder's Old Fashioned Peanut Butter (smooth), unsalted butter and both Splenda Bake White and Brown. Besides that it was only an egg, vanilla and some salt, and of course the King Arthur Flour Company's self-rising flour, which I bought at Safeway in Tucson.
You might think that substituting the sugars with Splenda might have an effect on taste or texture, but I promise you that the cookies came out perfect. I baked them in a jelly-roll pan because I am not crazy about rolling or cutting or whatever. They are sitting in my freezer right now, and I will repeat the process this weekend to take another batch to the coffee hour after church.
You could also use the stevia baking blend that is appearing in the supermarkets lately, although I haven't seen it in brown.
So for the purpose of cookies--and quick breads, probably--I think it is right on to use self-rising flour. And here is the recipe I followed for these cookies, adapted for exactly what I used to make them.
PEANUT BUTTER COOKIES
1/2 cup Splenda Bake White
1/2 cup Splenda Brown
2 sticks unsalted butter, at room temperature
1 large egg, at room temperature
1/2 teaspoon vanilla extract
1 cup old-fashioned creamy peanut butter (stir in the oil before using)
1/2 teaspoon salt
1-1/2 cups self-rising flour
Set your oven to 350 degrees.
Cream the butter with the sugars in a mixer. When they are combined, beat in the eggs until it is completely blended in.
Beat in the peanut butter, salt and vanilla.
Lower the mixer speed to the slowest setting and fold in the flour. When it is blended, spread the dough in a jelly-roll pan.
Bake the cookies for 25 minutes and check to see if they are done.
The original recipe calls for an oven temperature of 375 degrees, which would be good for individual cookies in the classic shape: drop cookies flattened with the tines of a fork. However, the gentler heat of 350 will protect your jelly-roll-size cookies from burning.
By the way, don't relegate peanut butter cookies to kids and your childhood. They are really good and quite interesting with coffee after dinner.
There is also the new favorite of making round drop cookies and pressing a Hershey's Milk Chocolate Kiss into the center of each cookie right after it comes out of the oven. And since Kisses now come in quite a few combinations, like chocolate and caramel, or dark chocolate, you can play with this and get some interesting cookies!