I was describing a hypothetical system such that congestion levels would be provable as they happen. For all we know our household connections could be artificially throttled during evening hours when the network is supposedly congested, while in fact they are trying to push us on more expensive plans.

In fact I am not against on the spot pricing schemes, as long as the demand and supply is provable.

I would consider such a system neutral enough. I wouldn't mind scheduling some datasets to download when network demand is low etc...