Brampton, ON, Canada < change city >

We are having a medium size wedding, about 100,(and I don't want over the top extravagance) but I would like chair covers for the reception (white, cream or silver are all fine). The venue will place the chair covers on for no extra charge. I have seen prices ranging from $2.50 - 10.50 per chair cover. Does anyone know a reasonably priced and reputable supplier?
Secondly, we are interested in doing a backdrop behind the head table. My fiance wants it to be 30 feet to cover the doors on either side of the table. Again - does anyone know a reasonably priced and reputable vendor (prices quoted so far have been from $65 for 10 feet to $750).