I'm not positive, but I don't think Prada makes this bag exactly as this replica is pictured. There is a similar style I've seen in person and online that doesn't have the buckle on the side. Here are some authentic online sites to check out. And of course, you can always try calling the different prada boutiques or Saks, Neimans or Barneys to see if they have it.
Prada does have an online site, but you have to choose a different country to view the handbags.
I think that's the fakers' (black) version of the cervo antik bag that is quite popular among many TPFers. (you can search the prada subforum for many threads about this bag. try keywords: ashley tisdale, cervo antik)
You can try Prada boutiques in Hawaii if they have any left, although this is not likely, especially since this bag is from many seasons prior. You can also try online auction sites (ebay, bonanzle, etc.) to see if anyone is selling theirs. Please do post your find in the Authenticate This thread first before you bid or commit to it.
This one is two years old and has the Train tag on it. The newer ones just have the plain ID tag. That's the only difference. The leather on these bag is to DIE FOR. It's calfskin, not deerskin. Soft as a baby's butt, durable and still after two years it smells like heaven. It's one of my favorites.