The SPACE I report (last published in April 2017) covers incarceration rates for each member country of the Council of Europe: http://wp.unil.ch/space/files/2017/04/SPACE_I_2015_FinalReport_161215_REV170425.pdf
Her Majesty’s Prison and Probation Service (HMPPS), routinely publishes average costs per prisoner and prison place, and overall prison unit costs of individual prisons for each private and public sector prison in England and Wales. The information can be accessed in the Prison and Probation Performance Statistics pages for each relevant financial year here:
https://www.gov.uk/government/uploads/system/uploads/attachment_data/file/563326/costs-per-place-cost-per-prisoner-2015-16.pdf. Prison unit costs can be found within the Excel document Costs per prison place and cost per prisoner by individual prison establishment in the ‘Cost by Establishment’ tab. The most recently published figures are for financial year 2015-16 and we expect to publish the 2016-17 data on 26 October 2017.