My T5's are showing signs of age ( 8 years actually) and still work quite well.
Has anyone sent their pipes out for re-chroming ? would it cost more than it's worth?

For the not so bad spots, try coke and 4 ot steel wool or tin foil. This does a very good job. Mothers chrome polish works great on the real light stuff and navel jelly from home depot works good on the bad spots. If you are unhappy with the way that turns out, then it is time to look into re-plating. My tail pipe sections are really bad. I have a friend bead blasting them as I type. I'm going to paint them with high temp silver since they can hardly be seen anyway

Try this stuff. I used it on a set of Toomey's and after about 1 hour of some rubbing they turned out great! Local Harley shops carry it also!
http://www.blue-job.com/