Someone asks on Reddit…
I’m looking to charge for an all in one solution for a flat fee of 2k a month. Website, SEO, marketing. I’m trying to think of businesses that can afford 2k a month without any big hassles?
The most up-voted answer…
The best niches in my experience are what I call the “oh shit” niches.
These are the companies you call when something happens that makes you say… ”oh shit!”
HVAC, plumbing, roofers, personal injury lawyers, auto collision repair, etc.
These industries typically have high volume/high ticket jobs. So $2,000 is chump change for them. They’ll pay much more depending on the size of the company.
What are the “oh shit” businesses in your area? 
They’d be good targets for pitching services like web design, SEO, lead gen, PPC, etc.
You could try the “drop servicing” approach here: hire contractors to do the work and you be the middleman.