Have a go yourself.
I think a good start would be to define what kind of servicing you want undertaken to your Ion.
If it a standard type if thing with lubing your bolt and cleaning bits out. Their are links on here to tutorials for you to undertake that routine maintenance.
If you want to take it a step further and clean your reg and your noid, again, their are links on here to tutorials for you to undertake that routine maintenance.
What else would you do to an Ion? Apart from of course changing o-rings and fiddling with the settings, but frankly once you have gained confidence in doing the above, these jobs are straightforward.
I think what I'm trying to say is take advantageof the on-line tutorials, and have a go yourself. Once you've done it once, you'll wonder what all the fuss is about. You'll probably make a few mistakes like we all have done, but that is part of the learning process.