We say every day, ‘and you shall love Hashem you G-d with your whole heart and your whole soul and with all you have’. ‘With all you have’ refers to one’s money, and even if we aren’t on the level to give up all we have for Hashem, we should love him at least as much as we love one of our children. Thus, a person should figure out how much he spends on each child, including marrying him off, and should spend at least that much to support Torah. And just like we spend money on our children happily, so should we spend money on supporting Torah with at least as much joy as we get from spending money on our children.