Like most answers to recruiting questions, there are so many factors to consider. Personally, if I'm going to pull a guy down, I want to do it within the first couple of cycles because once they are considering someone else, it's not cost efficient to pull down and then start a battle.
But I would say this, you need to get a feel of about what number rated recruits and and what distance of guys will give you a backup message, and then you need to see how good the players is, because if he too good, it's not worth pulling him down right away because it's likely a higher division team will go after him. So on those guys, you have to wait. But if you think you have a shot at the recruit and he's going to give you a backup message, I have, on many occasions pulled players down the first cycle. Just don't spend all your money doing it, and make sure not to throw all your money away if other people get on the list the same cycle just because you already feel invested in the player.