That is on the high side for a connection in Denver -- I think you are overestimating costs.
I looked in a poorer neighborhood in Denver (700sq.ft. house), which is clearly close to fiber, and from Centurylink for $65/mo they can get 940Mbps, for $49/mo they can get 100Mbps.
Looks like for $20/month, xfinity will do 25Mbps at the same address.