I'm heading off to college this fall and I'm trying to formulate a budget for an iPhone 4 plan. I'm know I'm going with the 450 minute plan at $39.99 and the 2GB data plan for $25. All my friends use Facebook to communicate, so I'm not going to get a texting plan. So I'm looking at 65 bucks before taxes/fees/etc. What would be a good estimate for a final monthly fee?