I have no experience on this. But, I think you should consider the condition of the computer, if the computers are new, the troubleshooting work will be less. If the computers are in network, consider the troubleshooting and maintenance work on the network as well. When the computer is down, how long you have to fix the problem? If the dateline is tight, the fee should be higher, especially if you need to work at night or midnight.

In my opinion, RM50-RM60 per hour is a reasonable price, but also can charge at higher price such as RM70-RM80 per hour...