This requires complex legal arrangements to ensure proper distribution of payoffs and risk-sharing to align the incentives of all parties involved. Secondly, infrastructure projects are long term and are therefore subject to various risks including those due to changes in policies, delays in clearances, etc.
Every event that delays the implementation of a project leads to cost and time overruns that in turn have a bearing on the techno-economic viability of the project or would necessitate revision in the price of the endproduct. Very often the infrastructure products are meant to serve public good which imposes a limitation on ability to determine their price.