If you had a good experience last year, and a great rep, and your parents were happy with your product -- absolutely sign up early, take the bonus, and keep things simple for yourself.
But if you're still exploring options or considering making a change, I wouldn't let a bonus keep you from doing good homework like checking references and determining what fundraiser is the best fit for your group. The right choice without a bonus (happy volunteers, happy supporters, nice profit) is way better than a wrong (or even OK) choice with a bonus.
We have a ton of tips on choosing fundraisers wisely. Check out these articles:
How To Choose a Fundraiser
How To Choose a Fundraising Company
Fundraiser Ratings: What's Right for You?