I've some experience of doing on-site SEO work for clients for whom I've been developing their website at the same time. It's always been added in as part of the overall package and the costing for the SEO work has never been explicitly separated from the main budget. The results have always been good, with me basically following best practice with on-site optimisation. I deliberately don't get involved with the off-site side of things.
Anyway, without rambling on too much, I have a situation where I've been asked to cost for on-site optimisation work for a new client - but I'm worried about how to qualify what is an achievable result. The site has around 30 pages, none of which are optimised at all currently. The market they operate in is pretty competitive but I'd be confident of siginificantly improving their SEO ranking. How would deliverables be structured for this type of work? Do you promise that you'll get the site to a minimum of position n on Google?
Also, out of interest, does anyone have any basic ballpark figures for what this type of work would typically cost for a site of this size? I'm looking more at a one off fee as opposed to an ongoing monthly service.
Grateful for any pointers on any of this!