Getting high rankings on Google isn't rocket science - - but what these "SEO Experts" do and what I do are two totally different things.
I concentrate on "On-site optimisation" - basically making sure that the important information that Google needs to see is on your website, easily visible to the search engine and in all the right places. This approach takes a couple of months to really start working properly but gives long term organic rankings that are unlikely to be affected by any future algorithm updates. Google loves quality, unique content - give it enough & this alone will get you first page results.
Most "SEO Experts" concentrate on off-site SEO techniques like link building - these methods usually provide results very quickly and very effectively and can produce more traffic than organic rankings alone, but new links need to be built every month to keep your rankings high. This kind of SEO also comes with risk, albeit a managed risk - - create the wrong links (from low quality or irrelevant sites) and it can negatively impact your SEO, so you need to be sure your "expert" really does know what he's doing. Also, the way google calculates your ranking changes from time to time - the penguin update about 18 months ago changed the way links affected ranking and because of this update a significant percentage of websites that employed previously acceptable SEO techniques suddenly found their rankings decimated overnight, almost blacklisted from Google.
My recommendation is always go with organic ranking, and if you need to boost it add more content via blog posts or by adding extra pages.