Harrinj, there is no guarantee that a recap would fix the buzz, since that could be a problem with the output transistors, or something much simpler. Best to have it looked at if you want to keep it.
In my experience, most "fix it" places will NOT do a full recap. That tends to be the domain of specialists. Most fixit places will replace only what is needed to get the item working again. Most charge a bench test fee, yes, but any reputable place will credit that fee against the actual cost of repair should you elect to have them do the work. And that's as it should be. They should not have to examine it for you for free and then have you take it somewhere else to fix it.