first client - Don't know how to pitch and price services - help needed

I'm a noob
I Ranked a local site (in UK). Sent out a load of emails last week asking if they would like to rent my site. 2 business wanted too, now I have a client who rents out site. I sent him an email telling him how bad his main site is and what I'd recommend to improve traffic, basic onpage/offpage stuff.

I get a phone call from his nephew today wanting too know what my pricings are (his words not mine) and what I would do to help his local site. After 20 mins on phone explaning some basic stuff we come to the agreement that I'd look at his site then get back to him later on today.

His site is easily helped, some basic onpage stuff and link bulding etc.

This is my problem: I have no idea on what to pitch, how much to charge, when to charge, how to explain things, how to get him to change his onpage stuff 'cause he havnt done website design etc.

Need help.

Edit: oh yeah his home page is targeting (if you can call it that) no search volume keywords, but all his inner pages, about 100 of them, target a small town/area in London area that do get a little search volume each.

You need to have a set price list before you start trying to sell your services. Make sure you avoid scope creep with all future clients, Google the term and make sure you have a read.

I would give him a soft landing. I would explain to him that my seo work will be ongoing to stay ahead of competition then charge him 15% of potential gross earnings over a six months signed contract.
Else 100% of the above for a one off job.