Long-term reliability, servicing, and repair are extremely dependent on a good installation. Avionics problems can be built in at the time of installation if the work is not performed correctly. Every installation should be neat, electrically well-designed, mechanically strong, and properly put-together. Instrument Overhaul designs in quality so your avionics package gives you years of trouble free service.
Several different factors will cause the cost to install a specific item to vary from aircraft to aircraft. The type of aircraft will effect the time required to gain access to mounting areas. Larger aircraft generally require more time to disassemble and re-assemble than smaller aircraft. Available panel space to accommodate the new equipment will vary between aircraft. Existing avionics may need to be relocated to make room for new avionics. Remote equipment may need to be installed to allow backward compatibility of the new avionics with older existing systems.The condition of existing avionics may need to be evaluated. Some installations require the new avionics to be interfaced with existing systems. For example a new IFR GPS may be required to interface with an existing HSI. If the existing HSI installation is showing signs of problems, those problems should be corrected to ensure the new equipment will perform without problem. If you own an older aircraft that hasn't seen an avionics shop for some time, it may be time to clean up some existing problems during the installation of the new equipment. The goal of a high quality avionics installation is to provide the owner with a trouble free package, that delivers the performance the avionics manufacture promised year after year.