I had my 2000 Boxxer rebuilt by Hippie Tech a number of years ago (when I was still racing DH). The cost was over $300, but the fork needed a lot of parts to repair crash-damage... It's not bad, and I would probably use them again for the Boxxer if needed... but it still doesn't feel quite as nice as when I had the same fork tuned by Shaums March at a clinic at Mt Snow...
One of the main reasons I lean towards Marzzochi forks is the service center in CA still keeps parts in stock and will rebuild any fork they've ever made (all the way back to the XC-series forks of the early '90s). I just had my '97 Z-2 and '99 Superfly rebuilt by them for about $100 each.