First I have to admit finding it difficult to spend that much on a tool instead of fabric, but my resolution to slipping fabric and cut fingers is a simple two-step process:
1. I use a strip of blue tape under the ruler -- usually marking the width I'm working with, i.e. 2.5"
2. I bought one of the suction grips for the shower at Harbor Freight and use it for stability and slice prevention. It's about 12" long and has a suction cup on each end. Think it cost less than $9. They also have several smaller, circular grips that work well for smaller rulers.