It is hard to say as charges will differ from region to region and the number of circuits you have will also need to be taken in to account.
Last week I installed new a consumer unit with 5 circuits being protected by RCD and two by RCBO. I supplied unit and updated main bonding to gas and water for £400. That included a conditional report on existing installation and EIC with schedules and they paid me in full, before I issued them with certs
