Shop Question

Hello! My 2008 Subaru Outback XT 5MT with 122k miles is having some problems, which I won’t get into for brevity purposes, but one of them is that there is a rattling noise when the clutch is let out, that goes away when the clutch is pressed down. Now I know that this is probably the input shaft bearing, and the shop I brought it to confirmed that it’s most likely that. The thing is, they are quoting me for a whole new transmission. Their justification is that since it will be costly to drop the trans and replace clutch/input shaft bearing/throw out bearing, I might as well get a whole new transmission? This will likely be about $5000. Now, I almost laughed out loud when the guy over the phone said this, but I am just wondering if I am being taken for a ride here? I feel like there’s no reason to scrap the whole trans, which has nothing wrong with it other than the input shaft bearing noise, just because you have to pull it to replace the clutch and associated parts. Input appreciated!