In 1998 i installed one with battery-backup feature costed me $2600 . Nowadays i think the average price is around $1500. However my brand is already extinct and i had my spoiled PCB changed to another brand costed RM300 working even better than the orignal one. The motors still function well. And the lock (magnetic actuator) burned once due to short-circuit by water and this is what may not be easy to get replacement especially if the brand is extinct from market.
* History is never past. Every day the things people did long ago gather invisibly around us.