While I wouldn't touch anything for that cost, I think you might find that newer people, who don't have any/many clients, might take $100/mo. However, they may not be very experienced, which could, in turn, end up costing you a lot more in the long run if/when your site gets penalized.
That said, there are plenty of 'gurus' out there, who swear that they have the holy grail of SEO methods, that might also ruin a site. This usually happens when they become enamored with high-end or riskier methods that lower level people don't have access to because of the associated costs.
In short, it might be ok to use a poor, struggling high school kid, who doesn't have enough $ to own his/her own blog network, and so is forced to write articles, leverage social media, do citations, and make some blog comments here and there.
If you just have a local 'brochure site' (thanks for that valuable term Schmitty) that you can replace easily (heck, people do these for $20 on Fiverr!), ask your teenage nephew if he has any buddies who know about how to rank websites. You might just find a great deal.