Shop this look for $140: http://lookastic.com/men/looks/light-blue-longsleeve-shirt-and-light-blue-blazer-and-black-belt-and-white-chinos/2866 — Light Blue Longsleeve Shirt — Light Blue Blazer — Black Leather Belt — White
Shoes: There are several options of shoes that could work for a conference. Just find a pair comfortable for all day wear - remember, conference halls involve a lot of walking.