Replacement of the cooling coil is quite a tedious task. The dashboard needs to be removed in order to get to the coil. The coil itself is a few hundred ringgit (not sure how much), and the services to disassemble & reassemble it it more than that. Also during reassembly, the electronics need to be tested in order to make sure it works. RM2k++ is reasonable. Ur mechanic will be able to give u a breakdown of the cost involved.
p/s did the same cooling coil replacement for in e46, n yes it cost me rm1.9k to have it done.