Recent research has tried to calculate the "total cost of publication" in the British academic sector, bringing together the costs of journal subscriptions, the article processing charges (APCs) paid to publish open-access content, and the indirect costs of handling open-access mandates. This study adds an estimate for the other publication charges (predominantly page and colour charges) currently paid by research institutions, a significant element which has been neglected by recent studies. When these charges are included in the calculation, the total cost to institutions as of 2013/14 is around 18.5% over and above the cost of journal subscriptions-11% from APCs, 5.5% from indirect costs, and 2% from other publication charges. For the British academic sector as a whole, this represents a total cost of publication around £213 million against a conservatively estimated journal spend of £180 million, with non-APC publication charges representing around £3.6 million. A case study is presented to show that these costs may be unexpectedly high for individual institutions, depending on disciplinary focus. The feasibility of collecting this data on a widespread basis is discussed, along with the possibility of using it to inform future subscription negotiations with publishers.