It has to do with being sponsored. You can be a sponsored student and the state covers the "sponsor fee." If you accept a non-sponsored spot, then you pay non-sponsored tuition for all four years and a state won't pick up covering that massive fee for you after the first year, and why non-res students can't get in-state later.
So that's how WICHE people get in-state, their state pays that sponsor fee. You can technically be a non-sponsored in-state student if the state can't fund a certain number of spots.
So the 50K cost is really just in-state + the accountable student fee of 25,571$
Accountable Student Support Fee - Annual fee for students who, upon admission into medical or dental school, will not be receiving funding from the state of Colorado or a cooperative state for any portion of the costs incurred in participating in their training program. (from the SFS page)
How much are your tuition and fees?
Tuition and fees (2010-2011) for Colorado residents is $30,334, and for non-residents, $55,905. Tuition normally increases about 7% per year. (from the admissions FAQ)
