It is tough with inaccurate broadband maps. The government site is terrible. People really need to confirm.
First off he needs to get an agent this is not something that an individual is going to be able to successfully navigate easily though it is possible. This Seth guy doesn't seem to really understand what he's doing which is understandable but he's in over his head. The article mentions he is 1/2 mile away from Comcast's access point. That's going to be an expensive buildout, the $50k-60k he's objecting to sounds right. That doesn't mean that Comcast might not eat a percentage of the cost for example neighbors also want broadband.
There may also be other fiber near him, for example that CenturyLink fiber. If he's marked as on net there may be another access point for Comcast near him (for example fiber that Comcast is selling to a 3rd party provider who might thus be able to give him access)
His comment about XO at $600 / mo being exorbitant is crazy. If there is no fiber in the neighborhood then the internet over bundled copper (which the article doesn't say they are doing but XO specializes in and makes sense given they started with a T1 quote) seems reasonable. Again he might be able to bring that down by engaging an agent to something like $200 / mo / 1.5mbs but he's not getting 50mbs for $50 / mo other a copper bundle.