So the potencial of saving 400h-800h is generated by hiring a candidate at least 21.9% (=400/​(35*52)) to 42.9% (=800/​(35*52) as good as the best.
This suggests AWF would not benefit from additional active grantmaking due to hiring the best candidate instead one at least 44.0 % (= 800/​(35*52)) as good as them, because both would save enough time to senior staff for the 30 active grantmaking opportunities to be found. Assuming part-time work with a salary of 65.9 $/​h (= 120*10^3/​(35*52)), hiring the best candidate instead of one 50 % as good as them would save AWF 60.0 k$/​year (= 910*65.9). So, at least under this toy model, earning to give may still be a good alternative for the best candidate.
However, I will stop this estimate now, because the time for the AMA is running out and I have to get ready for the beginning of the holiday that starts in Poland today. :)
Thanks for the follow-up, Karolina!
This suggests AWF would not benefit from additional active grantmaking due to hiring the best candidate instead one at least 44.0 % (= 800/​(35*52)) as good as them, because both would save enough time to senior staff for the 30 active grantmaking opportunities to be found. Assuming part-time work with a salary of 65.9 $/​h (= 120*10^3/​(35*52)), hiring the best candidate instead of one 50 % as good as them would save AWF 60.0 k$/​year (= 910*65.9). So, at least under this toy model, earning to give may still be a good alternative for the best candidate.
Happy holidays!