Is homemade laundry detergent really saving you money?

A couple months ago I posted about how I make my own laundry detergent. I have always read about how much more economical it is, but I never actually did the math to figure it out. Luckily, I have a friend who happens to have a family with an appreciation (and aptitude) for math. They took on the challenge of providing a cost analysis of homemade vs. store bought detergent and recently provided me with the results. Here is what Ray and her family have figured out based on her costs at our local stores:
We have yielded an average of 35 loads over 3 batches.
Batch #1 cost about $8 (for the Zote, washing soda, and Borax) Average of $.23 per load
Batch #2 cost about $1 (for another bar of Zote) Average of $.13 per load for 70 loads
Batch #3 cost about $1 (for another bar of Zote) Average of $.10 per load for 105 loads
Batch #4 cost about $1 (for another bar of Zote) Average of $.08 per load for 140 loads
Future predictions (until we run out of washing soda and Borax:
Batch #5 will cost about $1 (for another bar of Zote) Average of $.07 per load for 175 loads
Batch #6 will cost about $1 (for another bar of Zote) Average of $.06 per load for 210 loads

In between batches I use Purex which we purchase at Walmart for $6 for 32 loads ($.19 per load)
I will have spent $13 for 210 loads of laundry at $.06 per load. Purex would have cost me $36 for 192 loads. We've saved more than 2/3 the cost (and gotten 20 extra loads).

So I am happy to report the answer is YES, you do save money with homemade detergent. On top of the cost savings here are some other bonuses Ray highlighted for me:

In addition, for some of us carrying those bottles of detergent to the laundry room in the basement (100oz or multiples of smaller bottles) can become really difficult. And lastly, think of all the plastic bottles we’re NOT putting in to the landfill (or in the recycling pile).

And one more thing: I have two boys… the stuff works. I don’t need to say anymore than that

A big thank you to Ray and her family for providing the cost analysis and for giving the homemade detergent their stamp of approval. So, what are you waiting for. If you haven't tried making your own yet, you should. And in case you are really looking for the easy way out...look what I found at my local Walmart last time I was there, ZOTE flakes. That's right, they have already grated it for you- just mix and go, couldn't be easier than that.

Shannon