Montana appears to have the cheapest credit freeze laws at $3 per CRA to add or lift for non-victims.
I suspect the CRAs are embracing credit freezes because they believe it will make them money and stop legislation which might demand $1 credit freezes or even free credit freezes. And because if it ain't in the statutes, they can start diddling with the details.
Some states also place requirements, like Washington's that kicks in next year, to free or lift within 15 minutes, 24/7 I believe.