Is there a way to see how much "value" is assigned to the resorts or what a particular resort "trades at".
in RCI points, you know how many points you have to trade.
in RCI weeks, they have begun giving you TPUs ("trade power units" - RCI weeks is also called "points lite") that similarly tell you how much your trade is worth. you would need to be an RCI member to find out how many TPUs a week is worth (or ask a friend or friendly poster who is an RCI member to check it out for you).
interval international is still more of a mystery. you tend to learn by trying and finding out what others have reported being able to trade for.
for the most part, if you have a reasonable expectation of "like for like," you'll probably be fine.
also, paying members of TUG can see the "sightings board." on that board, members will post what they see with their deposits...so if their marriott can see an available week that your resort's week cannot see...that would help you figure out your relative trade power...