Starting "freelance" script editor -- how much should I charge for teleplays?

I have landed myself a gig editing scripts on these teleplays.

The woman I'm working with wants to know how much I want to be paid for my services, which are going to be 1) full grammatical edits, etc 2) formatting major edits, like adding act breaks, etc. -- the material is rough 3) fleshing out scenes, maybe moving things around, and offering creative advice about how things are working in the script and what could be changed to make it better.

I actually have NO IDEA what to charge. I am new to this (graduated with honors in the major but don't have work out there yet) and am going to even be studying a lot myself toward the beginning of this project in order to make sure I'm doing it right for TV as opposed to feature scripts, which I'm more used to. I don't want to charge too little though, since honestly it does take a very long time to edit these things, and I'm not currently working much. It's also not simple work-- the scripts are in rough shape, like I'm going to have to break them all up into their episodic subplots, etc..

How much should I charge, ball-park range? Hourly seems to be a weird concept since someone more experienced might take less time to do it, though I'm willing to put in the work for sure to do it right on my own and am a quick study. Page-wise could work and is certainly easier to calculate but when it comes to money, this is so awkward... I need at least a starting point. I don't know if it makes a difference either that these scripts are a work in progress, so it's not like it's guaranteed for the client either to end up making a ton of cash on them, though the person is pretty experienced in the way of getting these things to work, just hasn't done much original writing (hence I'm there.)

Help?