Do NOT compete on price. As has been mentioned, it's really hard to raise prices. (You can always discount for well-organized clients, that Schedule D with only one trade, the long-time repeat client, the client who sent you a referral, etc.) Decide what you're worth and stick to it, showing your full price on invoices with a discount shown if applicable.
Compete on the time you have to offer or your expertise or relationships or being available year-round or..., but not on price.