How much does an EICR cost?

Typically £150 to £300 for a normal house or flat.

The number of circuits is what drives it. A one bedroom flat is quicker than a four bedroom house with an outbuilding, and the price follows. Expect to pay more in London and the south east.

That price is for the inspection and the report. Anything the report says needs putting right is a separate cost, and you will not know it until the report lands.