These are most applicable if you have limited ability in sewing and costume construction. Most conventions have costume contests where they judge the construction of your cosplay. Welcome to Buy Cheap Cosplay Costumes sale at Cosplay-Shops Online store. Buy a drink for takeaway and use the seating area on the other side of the same floor. The judging process is quite secretive, spiderman suits and what they use to pick the finalists seems to be hidden.