I am really just trying to get an understanding of what everyone is talking about. So, when you say a "regulator Inspection", what do you feel is being done for your $25 to $35? At my store I offer what we call a spec check for $20. This is an external only service, but includes; a visual check of the filter, a gander at the hoses hose connections, pull back hose protectors and check by ferrules. A visual observance of the regs overall condition, noting any build up or corrosion. Checking the reg mouthpieces for holes or torn bite tabs. Next I put the reg on the flow bench and check (and note) the regs IP and verify it is within factory recommended setting. My flow bench allows me to check the IP at low pressure, say 300 to 500 psi and at high pressure like 3,000 psi. The second stages are tested on my magnahelic for cracking resistance and flow rate and it allows me to check for a positive flow after the breath. Finally I put the reg on a pony bottle and toss it under water to check for leaks.
I report all of my findings to the customer and allow them to make their decision. I will typically do this while you wait if you made an appointment, or overnight if I am off teaching. If you decide to leave the reg for service I will apply the $20 towards the full service fee. Total time here is 20 to 30 minutes.