In order to ensure good performance of cables in a fire situation, cables with Fire Rating are required for all aspects of the installation, MICC is only one of these, there are others which are considerable cheaper in cost and easier to install.
The two types of fire resistant cable are “standard” and “enhanced”, the type used depends on the type of building and fire alarm system installed. The use of “enhanced cables” is recommended for systems, in particular building in which cables might need to operate correctly during a fire for longer periods in excess of the norm.
If MICC cable is being specified for the installation then there is normally a reason for this and it should be justifiable by your designer / installer of the system.
With more info RE the building and the install I could point you in the right direction.