Hard to say cheap or expensive. Depends on number of teeth being replaced, material, lab fees and all, difficulty included

Quite fair

A cantilever Bridge using the molar as a support or the premolar as a support ya?

Its not a good idea to use a premolar as a support and bridge to the back to replace a molar   

Unless its using a molar at the back and bridging it forward to replace a premolar

ah alright. So using your molar and bridging to replace a lost premolar.

Do understand that you will be shaving down your molar and fit a bridge and eventually more work on cleaning and maintaining the bridge ya.

that doesnt sound like a good plan for cantilever replacement 

You're gonna be placing more stress on the pontic (the replacement tooth) as it placed further back in the mouth.

On the long run you may cause issues with the premolar (the support tooth)