Honda generator 3000is Carb replacement

OK, I let my Honda generator 3000is set up for about a year and a half in a storage unit. I know, what was I thinking. Anyways a buddy of mine who is a good mechanic said he could clean the carb and it should be fine. He gave it back to me the other day and altho it runs it doesn't run right. I spoke to him and it sounded as tho he got in over his head and now I might need a new carb. He suggested to me that I get a rebuilt one put on it. My questions is, can any motorcycle shop do this or does it have to be one that works on Hondas generators. Has anyone here had theirs replaced with a new or rebuilt one. Just wondering how much its going to cost me. I called a local Honda dealership and was told just labor alone is 120.00 an hour with about two hours to put it on. That sounds a little fishy to me. Two hours?