Best Grill Burner Suggestions

Is a cast iron grill burner replacement worth the extra money over the regular stainless steel versions?
I have an older grill that has been wonderful and now needs a new burner to keep me happy. While looking at all of the options that are priced around $25, I noticed that there is a cast iron burner that is $55 that fits my grill. Has anyone ever bought one and is it worth the extra expense? What is the difference? What advantages or disadvantages are there?
Also, does it grill any different?