Ok, I redid the title of this thread so more people will read it. Here's the original body of the post.
I went to a local rim shop and left my new aluminum MAF pipe and aluminum elbow for my Big Mouth kit to be polished. They said it'd be FOC (Free of charge) so of course I want to tip the guy. What's appropriate? I have no idea the value of the service. I was thinkin $25 or so...any ideas?

I went to a local rim shop and left my new aluminum MAF pipe and aluminum elbow for my Big Mouth kit to be polished. They said it'd be FOC (Free of charge) so of course I want to tip the guy. What's appropriate? I have no idea the value of the service. I was thinkin $25 or so...any ideas?