I don't think there are 100s, let alone 1000s, of low-maint customers that are thinking "hmm, this abuse issue is really a problem on my site, consuming at least an hour a month of my time, but I can't afford $49 to fix it".
Think about it, you're asking for $25 for a million checks. Typically that'll be sign-ups or some sort of interaction. So their volume is probably what, 10-50x times that. Even if they used your API for checking before anon comments, that means they're getting millions of pageviews/visits per month. If such a site can't afford a, I dunno, $199 plan, maybe they aren't worth dealing with.
If you really think you need a charity-level plan, perhaps include a contact link for "open source and educational projects".
Someone will probably point out some wildly successful freemium model. Suppose that's possible too. But even then you'll want to make a large gap between free and premium. No one wants to deal with $10/month business customers.
So... what is wrong with a "low" price?
Must pricing nowadays be all game-theory where you want to extract the maximum amount without any regard for underlying value or actual costs?
It's almost a meme on HN: "you are asking too little!" "Raise your prices, double your consulting rate!" "Businesses don't even notice bills under $4999!"
I'm from Romania where my "business" cell phone (with 1GB internet and basically unlimited calls) is costing me $7/month. My build server on AWS used to cost me $25/month. Nowadays I use my own machines so I only pay for some leftover storage and I get a whooping $1.50/month bill on my card. I pay $39/month for accounting.
No matter how great a startup believes their thing is, a business has to cover a lot of expenses and 100 super-duper-products to purchase do add up. At some point it might even make sense to say: yes, I'll have an employee waste 1 hour each month on this problem instead of adding another vendor/product/contract to the list.
And for people using this for fraud, it's gonna take more than a minute, and there might be even more damage. For instance, avoiding chargebacks on 0.1% would more than pay for itself. And that's a good selling point: "Our product will save you $x% a month". It makes it a no-brainer, instant ROI.
So getting, say, $995 vs $25 means he has to find 40x less customers! He can afford to spend a bit on sales. It's a meme on HN because it's true and us engineers have a terrible habit of repeatedly undervaluing things.
He could even offer a "pre-launch" plan if he's worried about startups not wanting to rack up bills before actually having customers. That way they can maintain price plan integrity.
Overall I feel HN/engineers (myself included; I have to force myself here) worry too much about edge cases and keep thinking somehow these cases will make a serious business.
Thanks
If you raise your price, you will only end up dealing with businesses that have identified a need for your product, and know exactly how much fraud and other issues cost them.
With your price as is anyone can use it for any purpose, including those that don't involve losing money because of a fraud transaction.
I considered using you for my site just to get GEO-IP. Sure, I could setup a geoip database myself and keep it in sync manually, but at your price point... it was a no brainer.
Plus I'd get threat analysis thrown in so I can know if one of my users isn't able to see the site because Cloudflare is blocking them for being a tor exit node.
But of course if you charge $1000 a month for that, I won't use it for 'any purporse'. I'll just use it for pre-screening new subscriber accounts (and not free ones) because that's the only time it'd make sense.
Remember, at $10 for $100, he has to convert 10x the number of accounts. People that are considering setting up their own DB usually don't fall into the category of "good SaaS customers".
This is something you can add to your own heuristic, but not really use as-is.