[LAU] Linux mastering services?

We're almost done with a 12-track, 40-minute-long CD, recorded partially in Ardour and mixed entirely in Ardour. We should probably get it mastered. However, "pro" mastering houses want like $500 for a CD. We haven't made that much money in a year. I think we spent a total of $80 on recording it. So, not likely that we'll be justify big bucks to get it mastered. I suppose I could run it through Jamin myself, and just hope for the best, but I don't know squat about mastering. Are there any Linux-based mastering engineers around (i.e. on this list) who'd want to take on a project like this, for a rate that we might be able to actually justify? -ken