The cost of a timing belt replacement will depend on where you have this work carried out. A typical independent garage would likely charge around £300, an independent Vauxhall specialist around £400 to £500 and a Vauxhal main dealer more again. Stellantis, the parent company of Vauxhall, offer fixed price servicing and for the Mokka it quotes £739, which includes changing the water pump, which is a sensible approach when changing a timing belt. We would suggest contacting a few garages in your area to compare prices before making a decision, but as a general rule we would recommend going with an independent specialist.