I applied to all 9, so that was probably about 350 or 400 give or take to apply . I think it was something like $150 for the first school and about 30 for each school after that. Rec letters probably cost $100 or so for interfolio and send out my personal statement for proofreading. I interviewed at all but CSPM and barry. Just about all of them I was able to use miles and hotel points or roll them into work trips, so they really did not cost me much outside of rental car and eating/drinks. I would say though if you need to fly somewhere and stay one night, all in you are probably looking at $500 (flight, hotel, car rental (you will need a car for most of the schools) restuarant and that)
Thankfully at the time I had a pretty good job and lived at home, so cost was not much of a factor, but I can understand an undergrad this being a lot (plus you will need to cough up about $1000 not long after you get accepted somewhere as a deposit). I will say try to combine NYCPM and Temple into one trip (both pay for the hotel and you can get a bus between the two cities for $10 each way that drops you off literally at the front of TUSPM). If you need to fly to the midwest hit up Scholl, then drive to either Kent or Des Moines, about a 5 hour drive. The other thing too is most schools that do not provide a hotel usually have $70 a night rates at very close hotels, make sure to look into that.