Am I getting a good deal?

Hello,
I would like to thank everyone for their advice so far.
Authorize.net has quoted me these standard rates:

Standard Merchant Account Rates and Fees:

Monthly Statement/Support: $9.95
Visa/MasterCard Per Item Rate: 25¢
Fixed Visa/MasterCard Discount Rate: 2.39 %
Monthly Minimum Discount Rate: $25

Authorize.Net Payment Gateway Fees:

One-Time Set-up Fee: $299
Monthly Gateway Access Fee: $20
Gateway Per Transaction Fee: 10¢

I haven't mentioned anything to them about how much business I expect
to be doing. What tips do people have for negotiating down the rates
I've been given? In what situations do the above rates seem fair?

Thanks for the help, - Dave