I'd have a go at doing it myself,the blade looks like a friction fit into two cutouts either end of the pedal.
Judging from pictures as I don't own a pair, it appears you would need to bend/flex the blade to allow it fit intothe cutouts .
This is guess work but remove the old blade which should give some idea of how it fits together, warm the new blade with a hairdryer/hot air gun this should make it less brittle and slightly more pliable.
Locate one end of the new blade into the cutout,then using a suitable sized wooden dowel placed between thebody of the pedal and the underside of the blade you should hopefully be able to bend the blade and locate the other end into the pedal body and then slide out the wooden dowel to remove the flex and let it sit in place properly.
This is a educated guess of how it fits together looking at pics on Google images,I could be totally wrong but as it stands it could be a cheaper way to fix it.