Just because there is a measuring cup with the detergent, it doesn't mean you have to use that much. I replaced it with 1/3rd cup and it's sufficient. For items that have stains, I use liquid detergent and let a spoonful soak into the stain before washing.
For added savings make your own detergent.
There is a lot of buzz
about liquid laundry
soap, but you have to mix up batches of 5 or more gallons at a time.
Instead, I have been using a dry mix of:
For the soap I used Fels-Naptha,
but also grated any extra soap I had such as the small bars from hotel stays. I
put all the ingredients into a zip lock bag which made it easy to mix
everything together. I add 1/4 cup of the mixture to a load, but you may need
more or less depending upon how hard your water is. You won't get many suds
with this mixture, but the laundry seems to be as clean as it would be using
regular soap powder.