My local shop tells me that new rules are due.
Not only for pressure testing but examination in cylinders with a camera for corrosion brought on by condensation.
This is due to some shooters (not divers) completely emptying their cylinders thus making the matter worse.
Costs in my area have varied between £30 and £60!
Also brand new tanks here in the diving shop are cheaper than any I have seen in shooting emporia adverts.

Being a relative newcomer to PCP I'm open to other views and advice.