In digital marketers' circle, most of them recommend Ahrefs because of its "Quality of Data". If we look at the plans the free plan (Trail) takes $7 (1,069.60 pkr) which is a huge amount for a student who just start learning SEO, especially in poor countries. I have a suggestion to make a plan tailored according to the needs of students which is not a cheap one or not a very high-priced tool but a moderate plan for students with specific features which are necessary for beginners SEO learners (especially from Third World countries), if you have any vision regarding the ease for learners (which I believe you have because of your free learning material) then consider this, if not then a big thanks!