Don't put a whole lot of thought into it. DVD burners are a "dime a dozen".... Just choose one that matches your case for that $20 price mark.
Newegg list => http://www.newegg.com/Product/ProductList.aspx?Submit=ENE&N=100007589%204093%20600003707&IsNodeId=1&name=SATA
Well, that's the problem -- one is a DVD Burner, one is just a DVD-ROM. Why are they priced the same? Is it just that $20 is the bare minimum price for the parts and materials, and that both are similarly manufactured?