Inexpensive EEG Devices?

Rustcycle akss: "To extend prior music generation experimentation, I'm interested in creating music via genetic algorithms using neurofeedback to assign fitness values. Does anyone have a recommendation for EEG systems that are affordable outside research institutions? What's the best system under $2k? Ideally I'd want a multi-sensor system so I could do sonification experiments to 'hear' correlated data from different regions, but I'd settle for a one or two sensor system for initial experimentation — so long as there are drivers for Mac / Linux. How safe / unsafe is the OpenEEG route?"