My answer was not related to price (it's a free and open market!) but mostly to the communication behind it:
Maybe you should focus on the value (rate limiting is not a value!) your product produces, the market you want to reach, etc., rather than just rate limiting because it's an issue addressed at almost every layer of the OSI model. If you sell your product as a developer, to developers, the developers will say why? because they know it's quite easy to set up a simple rate limit. Show us why rate limiting is not simple enough (I'm honestly with you here), and money will rain.
Why is your product better than a two-line configuration? if that question isn't answered on your home page, I'll say, "Wtf, does it have a pricing page?".
Maybe adopting a free-premium subscription model is better, in case you want to distribute rate limiting, but mostly I don't think it's about that, but maybe a company-level distribution, like, "I have a small business, I need to put something on top of it, this something needs to have permissions, accesses, etc, across my domain. If so, take my money."
I didn't want to sound harsh, but it's a finite game, and I'm against those! (recommendation here to read Finite and Infinite game)