It's geting to the point with some of our diving equipment it's more cost effective to sell it on every 2 years and buy new than to pay for servicing.
Lifejackets must be getting to that stage too - unless you have 100s of them.
EG
Regs to buy new £210 if you know where to look
Regs 2nd hand on THAT site £150 - £200
Plus a spare 1st stage left over to keep or sell at about £50
Service cost - £50. Haven't paid for a service in years