Hai,
So what about offering more cosplay contests?
the events are always crowed and there are so many different types of cosplay why not create different contest over the three days.
There are so many things you could do like have a chibi only cosplay contest, best crossplay contest, best magical girl, best ninja, best Harajuku, best goth Lolita, skits, groups, individual, duo,
just break them up so that more people can attend the contest they want to see and make it easier for people to attend other panels and participate more in the con.