Learn it yourself and run it in-house
You read, take a course, and start editing your own pages. The upside is total control and no invoice; the downside is that every hour spent learning is an hour not spent selling. Most people underestimate this: the first twenty pages take three times longer than the twenty after them, and the first audit usually reveals template problems that are outside a beginner's skill set.
It works best on a small site with clear service pages and a patient owner. It works badly when you are also the sales team.