For those who don't have these yet it may be worth paying the extra and grabbing them while you can...
I was passing through the Brisbane CBD this morning so called into Big W on the way through on the off chance they had restocked these. The manager I spoke to said he had none in the system and the tag had been removed from the shelf because he said this part of the RID lineup was a QUIT line. When I asked him to clarify what that meant exactly he said they are like a clearance line while stocks last then they are unlikely to carry anymore unless the supplier (Hasbro) REFRESH the line.
This may explain why they were only $20 as Big W have had Special offer Clearance Transformers in the past. $10 Powercore combiners, $10 TF prime dlx. $5 Legions etc.