I don't recall seeing too many dirt-poor RU international players. Maybe this is something connected with what Jeff Probyn said about "expenses" in RU varying according not so much to how far a player had to travel, as to whether they were any good or not.
They tended to be set up in jobs that allowed them a bit of flexibility to pursue their Rugby Union playing. That stated not many were rolling in it as a result. There is this myth that the All Blacks were basically professionals all through the 1980's but I have read a number of biographies of players from this time and this was far from the case. Many of the players from farming backgrounds only managed to cope by having the local community pitch in while they were away.