Couple points to add, from my own experience.
The prices listed are from the Quartermasters. Enhancements from Contacts are double the listed price.
Secondly, there are Level 1 TO's for sale, from Kalinda and Burke, but they are at about 40% of the Level 5 TO price here, (or 20% of the price of an enhancement that has been doubled because it's sold by a Contact.)
I don't know if the price goes down when their relationship with you goes up, I kinda gave up on them when I observed this price gouging.
