Here's how to make soymilk for $0.33 a gallon.

SoyaJoy Automatic Soymilk Maker         $124.00   ($136.00 with shipping cost)
www.soymilkmaker.com
or www.NOTMILK.com
1-888-NOT-MILK

Non-GMO Soybeans (Laura variety)        weight          cost         cost per lb.
www.fairviewfarms.com                            10 lbs.       $ 13.00         $ 1.30
1-888-526-9296                                      20 lbs.       $ 20.40         $ 1.02
                                                                 30 lbs.       $ 27.60         $ 0.92
                                                                 40 lbs.       $ 34.40         $ 0.86
                                                                 50 lbs.       $ 40.50         $ 0.81
50 lbs. *  (454g/lb.) = 22,700 grams

(70 grams of soybeans make 3 pints of soymilk in under 15 minutes)

22,700g / 70g   = 324 (3 pint batches) = 972 pints = 121.5 gallons 

soymilk cost:      $40.50 / 121.5 gallons =  33 cents per gallon

cow milk cost:    $ 2.80 per gallon

Conclusion:
For the price of one gallon of cow milk, you can make 8.5 gallons of soy milk.

This soymilk machine makes 3 pints in less than 15 minutes. You just plug it in, add the soybeans and the water, and push one button.  It also makes rice milk, almond milk and all other nut milks.

A 50 pound bag of soybeans is only $40.50 and included shipping.  Their farm is non-GMO (non - Genetically Modified Organism). The laura variety is a type that has no beany flavor when used for soymilk.