What state are you in? Are you handy with tools? Pull it yourself salvage yards are the cheapest way to go for oem parts (best parts there are). Sometimes you get lucky and find the right color in good shape, sometimes you need to get it painted, but it's still less expensive to take a fender and get it done rather than a whole car. E30 parts run 85-92 model year and there are lots of them out there.