... I suggest buying a prebuilt, seeing as he has to ask his brother just what kind of internet connection he has... Most likley he has little knowledge of computers/components and troubleshooting if anything went wrong.
Sorry but I don't know about computer prices or canadian money. But if you tried to build one yourself, if anything goes wrong putting it together, you'd have to know exactly what part went bad, or you'd be stuck. If you buy one from a store prebuilt, if its bad or messes up within (90) days or however long, you can return it and they'd take care of everything. Safer for computer illiterate.