Most thing cannot be defined as
Ice. Even the
Volatiles that are sometimes call "ices" have a melting point higher than 100 Kelvin (whcih leaves off Helium for sure).
Ice is a specific word.
I am basing of the general distribution of
water in the solar system, and that it can be used to produce Oxygen and Hydrogen fairly easily.
Cost for dstibution is entirely based on who can get it and what one is willing to pay for it.
Though they will need Nitrogen as well since the air we breath is not 100% Oxygen.
Simly put, the more things humans need for survival that we can get from other bodies in the solar system are less things we need to try to take away from Earth. Also the less stuff we need to take from Earth the less energy we waste trying to break that much mass out of our own gravity field.
In return, we can bring back stuff we either don't have on this planet, or things we have in low quanities on this planet. While a large surge of certain things will certainly drop their market prices, making some thing no longer rare means that they can be used more commonly in techology and could potentally solve some of out problems just because whatever it is can do something we need, but we don't have enough of it to make whatever it is practical.
Like say daimonds (to use a A.C. Clark analogy). The concept of the Space Elevator is grand but we still don't have the tech to make it work. What if we used daimonds? Well we can't because that would be expensive as hell and we have no were need enough to make daimond hard tube, or whatever it was that was needed to make it work. Find a daimond in space the size of a mountain, and that isn't a problem anymore. The price of daimonds goes the hell, but you can make your tech now.