use price aggregating websites, or price comparison websites e.g

http://www.google.ca/webhp?source=search_app#hl=en&sclient=psy-ab&q=canada+price+aggregator&oq=canada%2C+price+agg&gs_l=hp.3.0.0i22i30.3579.11477.0.13403.18.15.0.3.3.0.149.1376.10j5.15.0...0.0...1c.1.12.psy-ab.e-Yt_bXBBOk&pbx=1&bav=on.2,or.r_qf.&bvm=bv.45960087,d.aWM&fp=d4e2f822c3072b51&biw=1517&bih=666


http://www.shopbot.ca/electronics.html

http://www.pricebat.ca/#

http://www.pricegrabber.ca/

http://www.howtosavemoney.ca/savelog/best-price-comparison-sites-canada