One thing is for sure, optimising your website is all worth it. Why? First, you can generate more traffic. Second, you can get a good ranking in the search engines. Third, it can be a good technique to use to market your product, service, or the entire business.
With the benefits you are getting out of SEO, you get more value for what you are going to pay an expert to do it all for you.
Blackhat SEO is a technique used that focuses primarily on the search engines alone. The strategies being used here do not comply with the guidelines of a particular search engine like Google. Thus, the effect would only be temporary. When the search engine can sense there is a manipulation in moving up to the rank, then, the website will face a penalty. Some of the sites being penalised are now sandboxed. There are some that are struggling to be back on track again.