Less if the right-of way and track already exists (it usually does even if the station buildings and service have been long abandoned.) Service and routes are about abysmal funding, not access. There are rail lines and right of way everywhere. Local governments in the US know the cost advantages, which is why so many are rehabilitating and installing rail and buying trainsets for commuter and light rail service. Most even offer free or very low cost fares because they know it saves them $$$$ and attracts investment. Developers love having an active local station, it adds $$$ to property values, and with gas prices climbing, and property in crisis, that only increases. They will even pay a good portion of station construction or renovation. Many states even own, fund, or subsidize freight services because it attracts higher-paying industries and reduces highway traffic (one train can replace 200 trucks).
The rail industry was deregulated after Rock Island was abandoned (most routes were taken up by other railroads). Freight is booming. Railroads are required by law to prioritize Amtrak trains, but they often don't and the gov. takes little action to enforce it, beyond complaints by Amtrak. Lawmakers in Washington have been hostile or disinterested to support for anything beyond the NY-DC service (surprise surprise).