You are not at a competitive disadvantage with a 2% rate. That's a darn good rate. Your playing field is level, or slightly tilted to your advantage, compared to your competitors.
Alternatives like PayPal, Amazon Payments, or Google Checkout also charge a similar fee. Dwolla can be cheaper, but I'm not sure how many of your customers actually use it.
Checks by Mail don't involve a merchant fee, but there is risk of bounced checks. That 2% processing fee that you pay is not a tax, but rather insurance against bounced payments.