Participating toyworlds currently have a catalogue sale with outstanding discounts on Kreo http://tw.ginger.arlnet.com/?q=LatestCatalogue

Optimus Prime $30
Sentinel Prime, Megatron $20
Sideswipe, Ratchet, Prowl $10
Small Op, Small Bee $8

Sorry can't confirm prices on Bumblebee or Starscream as there weren't any left at my Local but I would chance to say no more than $20.

Good to see these finally offered at more than fair prices.