How much would this computer cost?

The other day, I got home, and was really tired. I plopped down on my bed, but didn't see my computer there. I hear a crack, and sure enough, when I turn on the computer, there is a huge black crack covering half the screen. I only broke the inner screen, so it still functions. But, I can't keep on using the computer with the crack in it, so I decided I should invest in a new one. Well, I have my eye on a Gateway computer. I don't want a huge computer, just a tiny netbook, and these netbooks start at $239.99. Let's say I wanted to buy one that costs $279.99. I would like to know what the total cost would be taxes, etc. included. I live in Canada, but I am not entirely sure what kind of taxes they would charge for the computer (HST, for example). Please don't make fun of me, I am only fourteen, and I haven't bought a computer before (my other one was a gift). Also, any ideas of how I could get this money? Something appropriate for a 13-14 year old. Another question. Can 14 year olds get jobs at places like grocery stores, clothing stores, etc? All answers appreciated, but serious ansers only please.