The following sites/marketplaces have a mix of SaaS sites, content sites, and affiliate sites. These are all generally higher value sites/businesses for sale (think 50k and up for many) and are often for sale at high yearly multiples.
If you're considering lower value businesses to purchase, these two will primarily have sites/businesses for sale for under 50k, but often considerably less than (eg. 1-5k):
As with all things, whatever you're considering buying from any of these sources, you're going to want to do your due diligence to make sure everything is above board.
https://microacquire.com/
https://latonas.com/
https://feinternational.com/
https://empireflippers.com/marketplace/
If you're considering lower value businesses to purchase, these two will primarily have sites/businesses for sale for under 50k, but often considerably less than (eg. 1-5k):
https://www.sideprojectors.com/
https://www.flippa.com/
As with all things, whatever you're considering buying from any of these sources, you're going to want to do your due diligence to make sure everything is above board.