I'd buy it directly from Module Master:
http://www.modulemaster.com/en/services/rebuild_info.php
It was 2-1/2 years ago, and I paid $53 for the unit (no price increase!) and $20 for USPS shipping.
As I used USPS / Canada Post, I think I may have avoided the GST and brokerage charges. If you get UPS to do it, I think the brokerage is something ridiculous like $50-60. Plus tax.
(That's why I get frustrated in buying my parts in the states. They're cheaper to start, but then you're into the ridiculous shipping and brokerage fees, or it's a seller that's been burned and wants too much personal information. Rant over.)
The install is super easy with clear straightforward instructions. Just be aware that mine had the Audi symbols, not Porsche, but for hundreds of $ I couldn't care less!