I recommend you start here:
Iggy's Bin of Facts
Regarding cost. I didn't pay a cent, but the tab to Yamaha was just over $900.
Including new gaskets, new head bolts (not reusable, they usually miss this, which delays the rebuild after the new valves/guides arrive), new coolant, new valves/guides.
Regarding damage to the bike, if your not burning oil, you can just ride. No worries.
Keep an eye on the oil level.
Eventually the valve guides can wear to the point oil gets by and out the exhaust.
But, that could be many, many thousands of happy miles from now. I rode mine for 10K after I first heard the issue at 10K. Never did burn any oil. Just got it fixed because it was winter and still under warranty.
Bump the dealer to see if Yamaha will cover it. Yamaha is now sensitive to the issue.
When my dealer contacted them, I believe they already had a repair parts list ready.
No resistance. They did forget the head bolts on the first parts order.
Yamaha has paid to fix some bikes out of warranty. They definitely won't pay if you don't ask.
The squeeky wheel gets the grease.
Mine got worse sounding over time and the sound came and went.
I have diagnosed several tickers over the last few years.
80% of the people who think they might have a ticker, because of subtle motor noises, don't have any reason to lose sleep.
If there is disagreement between knowlegable owners, you are either ok, or it is too early to get a dealer to acknowledge it. Either way, just go ride.
100% of the people who are embarressed by the sound of their bike, have a ticker.
When non-FJR owners ask "what is that sound?", you have a ticker.
Just curious, how many miles are on your bike?