Posted: 24/07/2016 at 20:38
Yep, 5k legs definitely more fun as if you have less experienced runners it might take them longer to run 10k which makes it into more of a chore than a fun team event. You'd want to advertise to local clubs and also at parkruns, and you'd have to have male, female and mixed team categories to appeal to more people - even in my old club we'd have struggled to get a team of four women out. Also I think a 'family' fun day based on running with no kids' race would be a bit disappointing.
Re price, I can imagine some of my teammates doing this if it were local to us and there were decent prizes, but we don't have kids, so we wouldn't be into paying loads to fund the activities. Maybe you'd want to look into making money from refreshment stalls etc so that runners wouldn't feel like they were paying for other people's kids.