Ravello LWB's are certainly a rarer shoe than Color 8 LWB's. I'll share my own story - I like Ravello the most out of all the rare shell colors. I started looking for Ravello shoes about 2 years ago. Within about 5 months, I found a Ravello LWB on the Marketplace in my size, and bought it. Then I placed myself on another Ravello list (Alden DC) and got a call regarding that shoe in about 3 months. However, this was during the recent glut of Ravello (which appears to have dried up).
Lesson learned: while it may seem impossible now, do your best to scour the Internets (including the Marketplace forum and eBay) for the shoe you want as well as put yourself on the list at Alden DC, SF, or TSM. While Ravello appears to be held up right now, you never know when the pendulum swings and all of a sudden you get a glut of some type of rare shell (which appears to be the way things are going the last 2 years).