Working on Numbers

Working Numbers on the Job offer I just got... I realized that will all my expenses that I'm anticipating, I'll probably end with absolutely nothing at the end of the month. The trouble is, that with my options, there's absolutely no room for negotiation. Sites I've been using so far are

• Rent.com <-- All the apartments I like are all 10 miles or more where I might be working
• Car Insurance <-- These guys are expensive
• Estimating Taxes <-- Too High :-(