I have heard of many Talmidey Chachamim who do it quietly with gevirim, in terms of support exceeding 20/30 thousand a year and chasunuos. But only top notch, established talmidey chachamim & marbitzey torah. R’ Moshe writes, though, that true yissachar zevulun was to split both the fortune and the learning (not merely full support). But one who supports a major talmid chacham certainly has tremendous zechusim!