Deejay, one thing I've learned is there is usually a deposit on the jars you get your gallons from. Where I am at the deposit is $4-6 per gallon jar, so the first time I picked up 4 gallons of raw cow milk it was $6 a gallon plus $6 per jar, so five gallons was $60. Subsequent trips have been much less money, but it's something you should check.
The first time I picked up some raw goats milk, one of the gallon jars shattered in my car (Infiniti G35 sedan, best car evar), but luckily the milk was frozen. Could you imagine cleaning a gallon of goats milk out of your car?