Dont forget too, that the set has been long out of Print...Something like 8-12 months after its release (could have been quicker)...Same goes for EX DRagons, if I remember correctly.
I just recently got done selling 2 Wailord EX's and they both sold for more than $40.
$41.33 & $52.00
Plus, on top of that, the rest of the EX's out of those sets averaged $10 or more...(That I sold..)