Agent Pombero, feel free if you want to and have the spare cash to throw around, but I don't think there's any need to spend $150 on flats for mostly commuting. Something in the price range daspydyr suggested(perhaps in metal so they can be recycled eventually rather than going into a landfill forever) should be just fine. For long lasting smooth pedals with little/no maintenance in wet conditions, Wellgo offers a large number of cheap sealed flat pedals that should suit your needs, as do many other companies. Just do a google search and pick something that looks good to you with good reviews.