I run with Homes for our Troops and it is $600 to raise in addition to the registration fee for the race. Quality organization with one of the highest donation ratings you will find out there. Would recommend in a heartbeat.
With most of the groups I looked at when researching, the fundraising amount was in addition to the registration.
Check out what each group is offering to see what fits your needs and interests. We get our racing jerseys, fundraising support, a dinner during race weekend, discounted rooms rates, and more. plus they are a great way to meet some awesome people.