nancy, the reason for the higher price of milk is the US Government price guarantee (subsidy) increased to around $18.00 per 100-weight of milk from around $13.00. The actual rate they subsidize varies from state to state according to some archaic formula devised to protect farmers in Wisconsin. The further away from Wisconsin you are, the lower the subsidy according to this formula.
The reason the price supports increased was to reimburse farmers for higher costs, including fertilizer, fuel, feed increases due to screwball ethanol policies, higher labor costs including minimum wage increases, and higher land rent costs.
It is reasonable for milk to be more expensive due to these costs. The price was artificially low for quite some time because the government guarantee did not change for over half a decade while costs went up significantly.
If I recall, the guarantee was about $10.50 10-years ago, so that's about a 75% increase over 10-years.