I've been invited to a fantasy/manga convention next year with the hope of selling my book to the masses (as it's a manga/fantasy book anyway). This potentially could be a big thing for me, but I'm just wondering - what would be the best way going about it?

I guess what I'm wondering is how many books would I need to bring with me? I know if I bring too little I could run out, but too much and I could lose out. What's the best thing to do? Play it safe or take a risk?

Has anyone done any sort of book conventions before? It will be my first one so I want to make sure I do well. Any advice is appreciated.