The cost in your example is far, far more than $10 USD a month. If you can set this up, your time is absolutely worth something and even if this is your area of expertise, you are now personally responsible for a critical piece of your internet browsing infrastructure.
There are tons of important details to keeping a critical service up and running almost all the time - even if you are competent in this, that is still time every month making sure it's running, secure and functional.
The only reasons in my opinion to DIY a solution would be a) learning, hobby or for fun or b) you have requirements that can't be met another way, like privacy goals.