Hello, my name is Mark and I will try to help you with this.
ESP stands for Electronic Stability Program. It works in conjunction with the ABS and traction control systems.
It needs to be connected to a suitable scan tool to see what code has been stored but most likely is a fault with one of the wheel speed sensors. Costs are difficult to estimate without knowing for definite the actual fault. However most garages will charge around £30 - 50 to connect a scan tool for the initial diagnostics. Depending on what they find they will then advise you any parts that are required and the labour cost to fit those parts. Garage labour rates can vary between £50 - 150 per hour.
The fault with the door lock is probably just a lock motor gone bad but again you need to spend some time to test it first. This should be around 1 hour labour.
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