Party SNG's . Profitable ?

I heard some people on another forum talk about how much Party's SNG's are a crap shoot. Is this true? I'm sure some of you are making a living off Party SNG's right ? How much would I make a day if I played 20 $5+1 SNG's / day ? I'm not a great SNG player but I could beat the $5's. I have an average of about 40 % ROI at the $5+1. How much would that be a day if I 3-tabled them and played 20/day ? I was planning on playing 5 hours of 3-tabling. Do you think I could play more by doing this ? I've never done it before.