Someone else tells me that you can...
a) "upgrade" to a $200/month package. That gives you free WAF and you don't get charged for 404 errors blocked by the WAF
b) after a month, you can then downgrade to the $15/month package.
Currently that website is costing me $92.45 per month to host; it makes more than that. But it's a bit bloody annoying. I suppose I should look into the above plan.
I discover that my main website cost me $365.15 in August to host (I think I've just shaved $40 off the bill); while my personal blog cost me $4.16 (I've just removed that bill entirely).