Need 4 songs mastered

I need 4 songs mastered. The all songs have finished recording bar one. The single is completely mixed and ready for mastering. The next two songs should be mixed within the next week. Style is rock but all songs sound different style wise which is what we love. Single needs to be mastered as soon as we can get it done really. The other three I would send gradually over the next two/three weeks. Wondering how much this would cost thanks.

Additional info:
The song is mixed and ready to be mastered. I don't have a hard deadline for this. I'm looking to master 3-5 songs. . I'm interested in working with a very experienced mastering engineer.