I just paid for the new unlimited plan, and haven’t looked back. I agree about the 300 searches per month thing. I feel like I run many more than that, but haven’t counted.
I did also try a bunch of side by side searches "for work" (so mostly leading to stack overflow) and they were the same results, more or less, for my searches between Kagi and Startpage.
One thing I found myself doing as I became conscious of my search quota limitations is going directly to sites and searching there using the local search. This doesn't seem like a bad thing but it's one more step in an already friction filled process. :)