I think your best bet is ebay. They go for about $100 and you would need to spend about another $150 to have them program it. Anyone who has an old one here is probably a result of the same thing that happened to you (mine was lights) so it's probably burnt out too. Good luck!
2007 E90 335xi - "Sera"
Installed: aFe Stage 2 DCI | AE Performance Exhaust | COBB AP | cyba Black Air Scoops | HPB Interior LED Kit | M6 Wheels | ER Charge Pipe | HPB LED Angel Eyes | Helix Intercooler
To Be: AR Design Catless Downpipes