abs: master cylinder went dry

[hammer2]

while bleeding brakes on 2000 grand prix se with abs the master cylinder went dry. I was on the pass rear. I filled up and continued to bleed that wheel. I got a lot of air and now it seems like all fluid without air. Can I just finish bleeding the other wheels or do I have to take it to a dealer to bleed the abs system? If so, how much does this cost?

thanks