When it comes to "cheap" you can host cloudron on a raspberry pi in your home. I would not recommend that since you expose a server running inside your home network to the internet and this always comes with a risk. Hosting at home is also not always the cheapest option, as your hardware needs to be purchased first and then run constantly what increases the electricity bill.
As mentioned before I can recommend Netcup (contracts available for german and international customers) since they are a reliable hoster and have good price/performance ratio. On top of that they have a preconfigured Ubuntu 18.04 LTS + Cloudron image for their VPS/Root servers so you have cloudron running out of the box. Prices for VPS capable running cloudron (1 core, 2GB RAM, 20GB SSD) start at 2,69€/month so there is little room for arguing about better solutions.
Finally it comes down to the question what you want to achieve. I started with renting a root server for 7 € / month and testing cloudrons capabilities. If you want to test it out, start with your own hardware and the free plan.
If you plan to use cloudron as your main infrastructure (mail, website, services) in production, do not hesitate to spend some money on it. 30$ Cloudron + 10$ for a root server per month is appropriate.