Baking From Scratch - Cost Of Ingredients

Does baking from scratch really save all that much money once you factor in the cost of all the ingredients?

Cost Of 1 Cup Of Self-Rising White Flour:

How Many Cups Of Flour Are In A 5 lb Bag?
Answer:  15 Cups

1 Bag Of Self-Rising Flour From Aldi (5 lbs) Is $1.39
$0.092 Per Cup
$0.28 Per Pound
$0.02 Per Ounce

1 Bag Of All-Purpose Flour From Sam's (50 lbs) Is $12.98
$0.086 Per Cup
$0.26 Per Pound
$0.0175 Per Pound

The flour from Aldi is cheaper because it includes rising agents.
A cup of flour costs $0.09.

Cost Of A "Packet" Of Yeast:

1 Packet Of Yeast = 1/4 Ounce = 2 1/2 Teaspoons

2 lbs Of Fleischmann's Yeast From Sam's = $4.38
2 lbs = 32 oz = 128 "Packets" = 320 Teaspoons
$0.03 Per Packet
$0.01 Per Teaspoon
A packet of yeast costs $0.03