Did a little research on this one. 
It's not so much about publishing the price list as much as it is about
saying ANYONE can get those prices. For example, you could publish a
price list and then disclaim it by saying "Subject to Negotiation" or
something like that.
The key is not to be perceived as non-discriminatory. If you let anyone
buy the service at the same price (non-discriminatory) you might be
confused for a "public utility" or "carrier," which gets you regulated.
We don't publish our prices but will send them to anyone who asks,
just to be sure there is no confusion on this issue. We can't, to stay
unregulated, open the doors to ANYONE who asks for space...we need to
enforce certain "guidelines" for being eligible for participation, or we
get regulated. I know it sounds kind of backwards, but thats the way it
works!
-J