I had a tatty Sport wheel that came with my car. I had a it retrimmed to sell on and it cost £110 + post and that was about as cheap as I could get it done. Most places wanted £150 - £200. I used this place www.royalsteeringwheels.com as he was all over various BMW forums and had great feedback. He also did the wheel on my Brothers old Z3M Coupe, which he wanted with a bit thicker padding and stitching in the M colours. Again, another fantastic job.
Here's some pics of the wheel he did for me.
This space is a sanctimonious shit-free zone.