I am far from an AdWords expert but a thread at WebmasterWorld named Please join the "fideladeloopiedoo" experiment sprung my attention. Basically, WebmasterWorld members are bidding on a keyword phrase that has no meaning or value to anyone, the keyword is "fideladeloopiedoo". After they bid on it, they are comparing what the bids suggested by Google are for each person trying it out. The spread is wild.
$0.05 -- $0.10 -- $0.30 -- $0.40 -- $5.00
An other member tried;
In a Campaign where my maximum bid is only $.04, fideladeloopiedoo requires $.03 to go active. In a Campaign where my maximum bid is $1.10, fideladeloopiedoo requires $.04 to go active.
Finally one member puts this all into perspective;
This is an interesting thread and should give some mathmatically inclined (or bored) individual an opportunity to work on their differential equations and develop some meaningful information. Let me know if any develops.