How difficult would it be for a B- team to recruit against an A- team? If both teams are within 200 miles, how much more money is the B- likely going to need to spend? Thanks

My first guess would be double the money.  That is very rough - keep in mind the grades could be at high or low ends of the ranges that those letters represent. Folks would have various estimates, but if you cant spend twice what he can, I would bet on him

2x is way too much. I have a full letter at somewhere between 60-70%, while others have it a little less. 

My guess is slightly less than tianyi's  (between 50 and 60) and remember these estimates are only for D1 (D2/D3 prestige differences are way way lower).

multiple issues here to determine your answer. First, almost no one agrees on the value of prestige for a true 1 letter jump. You'll find ranges of 50% to 100%. My number is naturally somewhere in between. No one wants to tell exactly how they value it, because then they would be giving away data that could help others beat them in battles... the other issue is that a B- to an A- could be a true letter grade, or it could be a high B- (borderline B) vs a low A- (borderline B+) is would be about 2/3 of a grade, or it could be the reverse and be over 1 1/3 letter grades. So basically you have somewhere between 2/3 to 1 1/3 letter grade variance at 50-100% bonus per letter grade.  So on $1000 effort for example, the very lowest end of both could mean the lower team would need to spend $1335, while at the highest end of both they'd need $2776. To tighten up those values more you need experience with battles and to determine where you think the values land. Note that those values I've given are very extreme on both ends. It is much more likely to be somewhere between say $1500-$2500 over a range of 2/3 to 1 1/3 letter grade... probably not much help, but I hope it gives you something to go on.*

*there is also every possibility that I mucked up my back of the envelope math...

2x may well be too much - IFFF one knows that the difference is exactly one letter grade - BUT, see dacj501 analysis about the actual underlying range of possible gaps and one will see that 2x is well within the middle of his range of possibilities. 

hard to know - and keep in mind that exact knowledge of this one bit of data doesnt accomplish much given that there are other variables relevant to decisionmaking - like promises made - how much of the budget your opponent has spent on other recruits etc etc

If I were the B- team, I'd want to know that I had 2x as much to spend. That doesn't necessarily mean the diffference is quite that much, it's not, but so many other variables are depending on fuzzy math, you really need a cushion, especially when you're the underdog.

Put me in the, "gotta have enough to double the effort" camp as well.  Which, unless you're a really good recruiter (and I am not), means walk away.

one more thing - which goes beyond the OP ratio question - you want that cushion to cover uncertainty because you really want to win if you choose to fight.  The cost of losing is not just that you dont get this guy, but maybe you dont fill a spot or two or you miss out one or two or even more solid recruits.  A failed battle against a Big Dog can set you back in a big way. 

Dont bring a knife to a gun fight.  Dont bring a an AK 47 when you really should have a bunch of RPGs.  If you fight, expect to win, not just to have a chance of winning - esp if you are the underdog.

anything more than 2 slots above me (for instance b- to b+) i tend to shy away from. If I'm in on a guy early and the higher guy comes in late, i may or may not battle depending on all other factors.

I will not go after the hiugher prestige guy unless he has way more player considering him than needed and i feel i can pick one off without him noticing.

all good info, at least generally. the double the effort idea is not a bad one, for the reasons mentioned, but also if you are a lower prestige school and this is your 1st school, theres a good chance the higher prestige school is more experienced. now, maybe not, maybe you have 3 elites in 3 different worlds, i don't know, it could be anything - but if you aren't really confident in your d1 recruiting, you have to allow that the other guy has you there, too. he could have spent his other money more effectively, maybe he spends more effectively on the given recruit, just generally its good to be safe. and remember, a lot of good coaches won't battle you if they know they are going to lose. you generally want to be pretty damn confident you will win when you put yourself in that spot. the more comfortable you get, the more risk you can allow yourself to take, and the tighter you can play that 2x ratio as an underdog.