There's one on ebay but that's the only blue RM I've seen for a while. I've been watching out for sales on chocolate brown myself. If you'd be interested in any other color Shopbop.com has a coupon until tonight that would take $100 off the price. The code, I believe is GETGIFT. Good luck!
The blue one is on ynotshop.com and they have a code for 10% off and free shipping. That code is WINTER. Also, there's a thread on the deals and steals forum about a code for 15% off the Rebecca Minkoff site. Hope you find it!
AW... I'm so sorry! The 15% off is for Hayden Harnett, another of my fav brands! But there is a code at ynotshop.com and I just saw the mini in blue on bagtrends.com but it's on backorder for 6-8 weeks.