As part of the startup, costing is an important factor that cannot be set aside. You do need the expertise of somebody who has some experience in the SEO space so that it can be fine-tuned accordingly. Also, as and when new features or so are updated on your website, you might need to keep updating the search strings for better narrowing it down.
Factors to Consider for SEO Decisions
Having said that, the basic factors that I would suggest to you for deciding are:
* Do you have the bandwidth to learn something new and then try it out?
* Are you short-pressed for time to start off something and, as mentioned above, drive customer traffic via the website?
* Would you be able to keep updating your SEO parameters on a regular basis automatically to keep up with new products?
If your answer to these questions is YES, then you are better suited to take it up yourself since you know your business better and would be willing to fight tooth and nail to make it a success!