Depending on where you live and what kind of competitions he goes to, prices vary. For example challenger series are the cheapest (he usually does Autumn Classic in Canada and all event tickets are usually around 80CAD) since they aren't as important as Grand Prix series or other ISU championships. GP tickets vary from country to country also, as well as from arena to arena, but good tickets (cmiiw) are usually from 200-300CAD. Worlds tickets are obviously the most expensive and vary from place to place, but decent all event tickets usually range from around 500-600CAD to 900-1000. So without counting accomodation and transportation, challengers are the better option, and from experience feel much more intimate and special since they are held in smaller venues.