Does anyone know about the quality of a universal chimney cap? It is more economical than our other choices but we have been told they are no good. The only problem is the person telling us they are no good is trying to sell us either a black one for $60.00 Can which apparently isn't great or a stainless steel one for $120 Can. I'm not sure the size of our chimney. Do those prices sound right? What type is recommended? Thanks for the input.