Are you willing to get your hands dirty with the work yourself to bring the total cash outlay down?
The average price of a SEO agency / freelancer is about $100. Having worked with video marketers (as one myself) you're looking at a total investment of about $2k/mo for a few months before you get an ROI from organic.
However -- if you're willing to do the writing to represent your brand and educate your users then you can save usually 75% of the total costs.
SEO is process oriented and outsourceable.
There are services that do all the technical work & heavy lifting, then give you the processes to finish the rest of the work with step-by-step instructions.
That is for the on-page and for any content marketing for the blog.
There are also link building software that I made that makes link building reductive and easy.
In short -- you can get links built with maybe an hour of time, with 90% of the work being done writing content for the other website so they can link to you.
If you'd like to have a quick chat, you can reach me here.
I have to agree with Jake -> do it yourself. You can learn how to do the technical part and while you will never be as good as an agency, it will be way sufficient for your first year(s) in the business. And for the non-technical part, i.e. content, you (or somebody in your team) will be the best at creating it. We can jump on a call if you would like some guidance, in particular for the content part.