What you could have accomplished in the same time at home. You have to take into account how much time you ‘loose’ by going to the event. However regarding your value – there is not really much advise I can give you. My family was not so keen on me and Rob being together, vision halloween costume especially at first. Being afraid to start asking for one does not only hurt yourself, but also the other guests in the long run since conventions will start to expect ‘that everyone else will do it for free’, so why should they pay you.