There will be a cost for building and maintaining the pipeline and the land it runs on. Who should have to pay for that- The ones making the Profit off it or the Taxpayers?
The pipeline is privately owned and would be paid for by the company building it.
Rights of way are leased for the pipeline, and any maintenance on the pipeline or necessary remediation of land is the responsibility of the pipeline owner. Frequently, such pipelines are buried well below plow depth on agricultural land, and the land above the pipeline continues to be used for agricultural purposes. There are definite regulations in regard to setbacks from occupied buildings, and the lines are (or should be) clearly marked. Surface facilities needed for maintenance, pump stations, etc. are also built by the pipeline company on sites either leased or purchased outright for the purpose.
Companies like Kinder Morgan, Enbridge, and Transcanada pay for the construction and maintenance of those facilities also, and have armadas of attorneys and negotiators who go forth in the planning phase to obtain the rights of way easements and clear up the siting issues prior to the pipe being laid.
Much like drilling an oil well, where everything has to be planned and approved before the dirtwork begins, the pipeline has to be planned, EIS filed, all surveys conducted, rights of way and easements and permits obtained before anyone strikes an arc and starts welding pipe together.
The taxpayers don't pick up that tab, it is all on the company putting the pipeline in. Regulatory shifts commonly contribute to costs even during the planning phase.
The only pipelines the government picks up the tab for are ones where the government is the entity installing the pipeline (usually for water). There are some government owned oil pipelines in association with the Strategic Petroleum Reserve that the taxpayers do pick up the tab for, but
For natural gas, oil, and other liquids, the vast majority of pipelines (the ones for profit) are owned and operated by equity companies. Cost of transport drops for say, a barrel of crude from the Bakken, from seven to fourteen dollars a barrel by rail (depending on destination) to $6.50 to $7.50/bbl by pipeline. Those savings can be passed on to some degree, but only if the pipeline option is available. Removing that pipeline option means additional costs to consumers at some point.
Government costs are the cost of regulation enforcement, and usually revenue (direct (taxes) and indirect (economic stimulation and sales/property/income taxes) from jobs) brought in by the pipeline and its operation more than offset those costs.