I'd like to provide a suggestion on how this might be addressed.
One way to make Kagi somewhat less costly for users in lower income countries and students, would be a pay-as-you-go model that combines with cached searches as suggesed above. This is more or less how I envision this:
a) One would purchase non-expiring pre-paid credits, denominated in USD. There would be a minimum of, let's say, $5, making it the same as the Starter pack.
b) Similar to the Starter pack, $5 would allow 300 new searches (more about the concept below).
c) To make it clearly different from the Starter pack, these credits wouldn't carry AI features. This would slightly compensate for the fact there's no recurring monthly income for Kagi in this version.
d) Atop that, any search done while logged in with a pre-paid credit plan would show a cached version of a similar enough search first, if it exists. Cached searches would be free. This would allow pre-paid users to effectively have more than 300 searches available, though how many more would be random, but it'd help. (This could also be part of the $5/month subscription, enabled by default.)
This way, regular users would indirectly subsidize pre-paid users by having simply used the service. The more users Kagi has, doing more and more searches, the more this cache would fill, and the more it'd return results for pre-paid users. For people researching recent new and events it'd be a god send.
e) Finally, a pre-paid user would see a button to resubmit a cached search if they think it's too out-of-date (the last time it was updated would need to be visible). Pressing the button would spend a search, reducing their total, so pre-paid users particularly worried about costs would think twice whether they ought to spend a new search on it or not.
The result of this is such users would have an incentive to use Kagi as a secondary search alongside Google, DuckDuckGo and others, opting to use it sparingly, mainly when the others aren't returning good results. Once they're in with a $5 pre-paid / 300 searches package, they'd be willing to recharge it for $5 more when those searchs run out. Then, over time, they'd feel incentivized to use Kagi more, reaching a point they'd notice they're close to regularly doing 300 searches a month, at which point they're hooked and would likely switch to a Starter subscription, gaining its AI features. And then, as it happens with people in the $5/month tier, they'd eventually see the benefit in upgrading to the $10/month tier.
And an extra suggestion:
f) Pre-paid packages of 300 searches for $5 might be available for those in the $5/month tier too. As in, one might subscribe to the $5/month package getting 300 non-rolling seaches, but if one month they needed to use a little more, then rather than upgrading to the $10/month package, which might be too much for them, they might make a one-time purchase for 300 extra non-expiring searches. Those would remain available and be spent in following months, and whenever they had to (temporarily) downgrade to the pre-paid AI-less tier.
As a perk for subscripters at the $5/month tier, differently from the AI-less pre-paid tier, these packages of 300 searches for $5, when used in combination with a Starter subscription of $5/month, would include AI.
Evidently, I'm suggesting 300 searches for $5 ($0.0166.../search) just to reuse the numbers already on the site and in the discussion above. It could be, say, 250 searches for $4.50 instead ($0.018/search), or whatever other ratio you believed would balance better.
I hope this helps!