You can buy discounted equipment from music stores/mail-order.
You can get installation advice from the sales person or those that are familiar with their home stereos.
You can have portable equipment with handles, black carpeting, and temporary connectors. A “club” system.
You can have heavey rubber cables all over your floor.
You can return to the store for more equipment when your sound is not right.
You can ask your musicians on what they want, all of them, especially the new ones.
You can keep improving your sound(?)
You can, maybe, sell the equipment you end up not using
OR
Engage an audio engineer who specializes in sancturary sound. Discuss your exact requirements to enhance all aspects of your services. Have a system designed to meet your expectations with speaker and microphone specifications selected for specific applications and to match your sanctuary décor, as much as possible. Accurate equipment positioning, neat, professional installation practices, digital signal processing, precision system calibration, substantial warranty coverage, and on-going technical support for regular and special programs, a buffer between you and manufacturer/warranties and the training of your personnel to operate the system.