Hi, I'm fairly new to the technical part of photography and I need some help with buying a wide angle lens for my Canon EOS Rebel xti (digital). My friend is a realtor and will pay me to take pictures of his homes but says I need a wide angle lens. My local camera shop today told me I should by the 10-22mm Canon lens for $799! They said anything else I buy would basically be junk and a waste of money. Does anyone have any suggestions on a wide lens I could buy for less money to get me started on this job? I don't have the $800 right now and I've seen a lot of other lenses out there that are much less, as little as $30 on Ebay but I have no idea what to get. Please help!!!