The core economic value of net neutrality is to remove the extensive cost of considering highly complex options that could appear if ISP's were suddenly able to start doing whatever the heck they want, including throttling particular sites, users, etc., at different times, rate plans, etc.. Seriously, you'd have to get a Ph.D. in your local ISP's practices to even begin to make an optimal decision for yourself, and the market simply can't barebear everyone spending that much time on a single economic decision.
###Value of regulation = benefits - costs