You asked

I am looking for the expected price to pay per square metre of floor space for a small office in the Oxford Road area of Manchester possibly near the university.

We said

Thank you for your enquiry.

Unfortunately, we do not hold information on the rent of an office space in Manchester. The Valuation Office Agency publish the "rateable value" of commercial properties which users can check. Rateable value broadly represents the annual rental value of a commercial property.

https://www.gov.uk/correct-your-business-rates