I recently on my Turbo Vado 5.0 'Big Boy' bike with new Como handlebars and the Kinekt suspension stem had to extend the cables.
I did it myself and completed it fine.
Yes, had to drop the motor, do all kinds of crazy stuff, etc., but it was a success.
I'd be a little hesitant to do it again though on the new SL 5.0, so if $350 is a kind of "going rate", I'd gladly let someone else do it.
However, before I commit, I'd love to see different angles/shots to be assured that is what I want.
When you have time and are back it would be great to get some photos. Alternately, I could always take a bike ride