[mkn]

The cost per kg currently around $10k, about half what it cost on the shuttle. If you assume a payload mass fraction of 2% and a vehicle mass fraction of 10%, you have a fuel-to-weight ratio of 44:1. So, it takes--switching to English units because milk is in gallons--44 pounds of fuel to launch 1 pound into orbit on current launch vehicles. Fuel is roughly as dense as water and roughly the same cost as milk. So, about 6 gallons of fuel at $3.50/gallon. $21 in fuel for 1 lb of payload, then.

How do you solve this problem? You work on the difference in engineering cost between $21/lb and $5k/lb, say by simplifying systems, building them more robustly so the $30k paper trail that guarantees that the otherwise $700 part will perform exactly as advertised goes away, or aiming for reusability.

Of course, if you did that on a large enough scale, you'd be Elon Musk.