Depending on what Yale lock you have and why it needs to be changed will depend on the price. If you have a standard Yale lock and you just want change the lock to give you new keys, you can normally just change the Yale cylinder or Yale barrel, the cylinder is the part of the lock on the outside of the door where you put your key into. If you have a faulty Yale lock or a standard Yale lock and want to upgrade to a high security Yale lock it will depend on what Yale lock you currently have on your door and which Yale lock you want to upgrade to as Yale make several rim locks. Remember Yale is just one manufacturer. You could have on your door or upgrade to a Ingersoll lock, Banham lock, Era lock, Union lock or Asec lock. So there is no definite answer to how much it would cost to change a Yale lock.
Chubb is a brand of lock and there are several different types of Chubb locks and it depends on which Chubb lock you have to how much it costs to change. Everyone refers to their deadlock as a Chubb lock but there are several manufacturers with each manufacturer making several types of lock and it depends on what lock you have currently in your door to what lock you can change it to which will then effect the price. So there is no definite answer to how much it would cost to change a Chubb lock.
The cost to change your front door locks depends on what locks you currently have in your door as there are several manufacturers of locks with each making a number of different locks. Some manufacturers make it so that once you have there brand of lock in your door you have no choice but to swap the lock for a like for like replacement but for some you can just change the cylinder/barrel, the outside part of the lock, to give you new keys. Likewise with certain deadlocks, not all deadlocks, you can change the internal components of the lock to give you new keys, keeping the body of the lock.
Banham have made several different types of locks over the years and have recently changed their keys as the patent on the older cylinders has run out so anyone can cut keys. On some Banham locks you are able to replace the cylinder to obtain a new key but with others you need to replace the whole lock.
Ingersoll locks are one of the best locks on the market and there are several different types of Ingersoll lock.