For a story about the costs behind open data, KPCC requested contracts for open data portals around Southern California.
In the contracts folder in this repo, you'll find those. They include contracts with three separate companies in the field, Socrata, OpenGov and Junar. The name of the municipality and the name of the company are reflected in the contract's filename.
All contracts were current as of May 2015, when they were requested. They can be downloaded by right clicking on them or by clicking the "raw" button on the PDF page.
Information from each contract, including the cost, contractor, city population and more is collected in data_site_contracts.csv.