@Haimy
The question of what a reasonable salary for the founder of a frum charitable organization may be absolutely meaningless. Many were founded by volunteers who never drew a salary. You need to ask what the paid executives of the charity are receiving as salary.
BTW>>>
A charity that pays its CEO 100K but only raises 1 Million is paying too much,
but if it pays 100K and raises 10 Million, the salary is a bargain