A good friend of mine is a Triumph technician , in Blighty a full dealer service with shim adjustment is minimum £800 . Of all the Rockets he has done , if the bike has been looked after , rarely are adjustments needed at 20000 miles . If ever they do need tickling , it has only ever been 1 or 2 at the very max .
Checking them is a fairly painless job which you can do yourself with a manual and a bit of patience . If any are out of tolerance , then is the time to contemplate weather to do them yourself or take to the dealer . Better that way than to be charged £80 an hour to to find they are well within tolerance as I suspect they will be ! As mentioned above , bucket and shim tolerances close up as opposed to opening which if left unchecked will cause headaches in the long run .
Go on , bond with the beast. You will be glad you did !