Basically take the amount of usages you use of Prerender.io per month, and compare it yourself.
What do you mean by more code to insert? I do know of Prerender.io but more code depends on which framework/language you're using. If it's node. It's pretty much one line.
The extra code is just options that allow you to customise the way the interceptor works, these options include things like blacklist, whitelist, regex, extensions ignoring, client side caching.. etc. But the basic usage is the just key + email, and you're good to go.
Also note that unlike Prerender, our cache storage is free, so we don't track how many pages you have.