First and foremost, make sure that your price fits the target audience, topic, competition and image in the marketplace. As with any product, your event is "on the shelf" next to competitors and other options. If your price is too high relative to your customer's wishes, they will go with another service or just do without.
Register now, pay later
Why do so many products offer payment plans? Because they work! Offering payment options can be an excellent way to get your customers to sign up immediately. If they can pay over time, they may avoid budget challenges and constraints. Offer "register now, pay later" or an installment plan if your organization can accommodate the accounting practice.
Who doesn't like getting a deal? Discounts are an easy way to promote attendance and they are proven to create urgency. Give discounts for early registration, group registrations or to those that register for more than one event at a time. If you offer a certification of any kind, offer a sizable discount for registering for the whole series up front.
For an event? Yes! Offering scholarships to a qualified person or group is another way to attract your target market without burdening them financially. It could be for kids to attend, for non-profit attendees - just about anyone you deem appropriate. Plus, it's a feel good thing for helping someone out.