Absolutely correct and my term original plan was incorrect - originally specified at just short of 12k but soaring costs, the methane ventilation issues and some definite council detractors saw a plan that had the west stand identical to the east one - fortunately a compromise was reached and a reasonably respectable west stand was the outcome.
The original spec was around £12k, but had the athletics track around the pitch and (I think) just two stands. That changed to a separate athletics and football stadium which obviously cost more, and as you say costs increased significantly due to methane management and ground quality issues.