Unfortunately, we don't have any control over the hosting providers' policies. One possibility is that they're charging for this because they haven't managed to automate it in their infrastructure, so maybe they have to have a human support agent help with the installation every time.
In this situation you would actually save money by getting a paid certificate from another CA, which might be valid for either 1 year or 2 years, and can be cheaper than $((4×10)-10).
If you do have root access on a VPS (as opposed to shared hosting), you can probably do it yourself without paying, so you might want to check what kind of access you have.
If you want to look at other providers, there is a list of shared hosts that provide support for Let's Encrypt, generally at no extra charge: