I am sure more than one Yeshiva is doing this, imagine if 10 yeshivas are doing this and every one of them goes down Bedford Ave (You might as well go where the money is).
I dont belive that every single one of them gets $100, If there are 10 fancy limos, thats $1000 which is alot of money even for someone on bedford Ave.
If it takes more than a few mins to get the money, it slows down the process and less homes can be visited. I guessed 3 hours for this, but if it longer, its longer and the Fancy Limo will cost more.
In best case here, with 5 hours of collecting . At the CHEAPEST rate quoted here, $100 an hour (including tip) and the most optimistic gain of $2000
that costed you $500 for a $2000 gross with a net gain of $1500 and a 25% cost to make the money.
And thats assuming you got the cheapest Limo with the most generous donors