Don't you have rate-limits? And how much are you paying for the instance where you're hosting it? I've run/helped run projects with something like ~10 req/s easily on $10 VPSs, surely hosting HTML can't cost you that much?

Of course it won't be free, but you can get pretty close to free but employing the typical things you'd put in place to restrict the amount of resources used, like rate-limits, caches and so on.