Depend on the brands.
Inflator Service Tool w/O-Ring Kit
Viton BC Power Inflator O-Ring Kit, Five Pieces
Extra set of O-ring
For the grand total of $11.00.
Video for free.
I don't think it does... because I said "having it serviced", not "servicing it yourself".
Unless you find a place that will give you free labor, having it serviced will always be more expensive than replacing it yourself.
Yes, servicing it yourself is even cheaper. Having done it myself, once, I will happily pay the extra $6 or so to eliminate the aggravation and to know that I have a brand new inflator.
The service kit only includes a tool and O-rings. It does not replace any hard parts that may be corroded. The kit also says it does not work for Aqualung, Cressi, Genesis, Mares, Oceanic, and ScubaPro. That's a lot of brands.
Find a little corrosion in there and now you've got some cleaning to do, which requires more time and "tools". And when you're done, is it truly as good as new? Probably not. So, how long before it starts to stick again?
Like I said, I've been down that road. If my inflator starts sticking, I spend 5 minutes and $17 and I'm done. Only tool required is a cutter for the zip ties. No chance of surprises that make it take longer or make it where I end up replacing the whole thing anyway. No tool or O-rings that turn out to not fit the specific inflator I'm working on.
But, that's just me. The $6 you save may be totally worth it, to you.