Don't quote me on this, but I think where I am, I came across an advertisment for a position you are describing, and they were offering in the range of 9-13 an hour. It's been a long time since I saw that add, so like I said, don't quote me on that.
As far as advice. Invest in a good pair of ear plugs or other similar types of hearing protection. It can get quite loud with APU's running and you're pumping thousands of pounds into an airliner for 15-20 minutes.
Good luck. I don't think it would be a bad job.
I haven't seen anyone start below $12/hr but maybe that's just my area. While I make more than that, I really couldn't see myself working as a line guy if I was making less than $10/hr. Sure I'm around airplanes and all. But it's a lot of stuff to put up with (a lot of hazards) and you need to be compensated reasonably for it.
Also, this goes with any job you ever apply for (that doesn't have a fixed pay scale). Never accept the pay they first offer you. I never have and I've always been able to get a bit more money which makes a big difference over time.
As for not accepting the first wage they offer you, be careful. Most places are pretty rigid in the pay scale, and have the attitude of "If you don't want it, this guy over here will take it."