they pop up on ebay from time to time.... or you could try this jacket maker on etsy 
and apparently the official one might get restocked... i wont hold my breathe though.... look here
They don't pop up on eBay from time to time as they are NOT the official jacket, the ones on eBay are cheap and most likely of poor quality, apparently with leather jackets any leather jacket that costs under $300 is unlikely to be of good quality.
I had a horse a couple of years ago, we bought a saddle for him for £125 from Ballinsloe (Ireland) fair. The saddle started to fall apart within months. We ended up buying a second hand saddle for about £250, it was 10 years old but was made by a reputable Irish saddle maker. Despite being 10 years old it was in excellent condition.
It's highly likely it's the same with the leather jackets, the official one will last years, the unofficial ones won't