Rates are reasonable, and -provided we have an accurate description of the equipment and problem- you would normally expect to see an engineer turn-up with spares and software, ready to perform the necessary work without delays.
Unlike some other techsupport agencies we prefer not to make any brash statements about response-times. Instead we prefer to be honest, and say that being a small outfit we cannot guarantee the instant availability of an engineer, at any time a contingency arises. I think you will find though, that waiting-times are in fact much shorter than those you would experience from a large and highly bureaucratic organisation whose engineers are often bogged-down in 'red tape' and procedural delays.
Our existing clients will testify to the fact that mission-critical problems are always dealt with in a highly-efficient manner. This is partly because we try to envisage such situation at the time of install, and plan for disaster recovery - a factor which many other installers overlook. A growing number of software problems can be dealt with remotely, given a broadband connection. We suggest you try this service first, as it may save cost and lead to a faster repair.
Common spares are available for standard computers, etc. For printer maintenance the policy is to farm-out the work to specialist repairer we have a working-relationship with, it being uneconomic for a computer-maintainer to also carry a full range of spares for all printers. Likewise, tools and equipment are carried for network cabling jobs, thus minor additions and alterations to network cabling can conveniently be made at the same time as computer moves or repairs. However for very large jobs requiring substantial manpower, we may choose to subcontract to a firm specialising in wiring.