I really don't know squat about friction drives or GEBE kits, honestly. I do know one guy who has a friction drive setup on his bike, and gets his rollers for about $.25 each and a few minutes work. He swears they work just fine in the rain.
He goes to Goodwill and buys old hard maple rolling pins. Takes them home, pulls the handles off, sticks the rolling pin in a jig he made for his table saw, and cuts 1/4" deep kerfs down their length with about 1/8" thick ribs between them, then saws them into 3" long sections - typically gets 3 per pin. Then he presses a T-nut in each end, and threads his shaft through them.
Sure, they wear pretty quickly - but they only cost a quarter and 10 minutes work to make, maybe 5 minutes to change out.