From the events website: "You can enter our individual series races for just $2.00. Students get FREE entry. Just fill out the Weekly Waiver to give, along with your $2.00, to race staff on Saturday morning before the race.
If you sign up as a member of the Roxbury Road Races Club for $25.00 for the year, that pays for your entry in all series races, not including the half marathon and marathon. And you just fill out the Season Membership form and you don't have to fill out the Weekly Waivers any more for the rest of the season."