Originally Posted by whataracket

Ah! You are taking the clipless pedals off.

All the plastic plain platform pedals I've seen were just test ride pedals that are put on new bikes. I wouldn't trust test-ride pedals to stand on over and over again - they feel like they'd bend. Good platform pedals generally have a metal frame even if they have rubber or plastic treads. There may be carbon fiber ones out there but they wouldn't be cheap.

I would suggest posting an ad on Craigslist in the bike section saying you want to buy somebody's cheap platform pedals, or go a to a local bike shop and ask them if they have any take-offs they'll sell you cheap. I would think the price range would be free to $10. I've given them away in the past.