If it actually does cost them more, then shouldn't they be trying to bill their own customers for what it costs? (I don't believe Pai for a second when his document claims that ISPs cannot figure out how to bill users for bandwidth).
What will they do if Netflix tells its customers on Comcast that their bill is going up unless they switch to accessing Netflix via a VPN? Will Comcast then start blocking VPNs? So then I cannot work at home? (My office went 100% work from home a couple months ago, so that would be very irksome).
Finding alternate revenue streams is fine...but I don't see why they should be allowed to stop me from using the service they sold me in order to try to convince some entity, which they have no relationship with other than that they and that entity have mutual customers, to pay them something.
I'm fine with it if my ISP wants to find alternative revenue by establishing some kind of relationship with outside sites and selling them something, just as long as the ISP continues to provide the service they sold me, on the terms they sold it to me.
For example, something like AT&T's "sponsored data" is fine. That lets sites pay AT&T to not count data AT&T users exchange with those sites against those user's AT&T plan data limits.
That's fine because AT&T's customers get the service they paid for. If a site buys "sponsored data" some AT&T customers get more than they paid for. If a site does not buy "sponsored data", those AT&T users that use the site still get what they paid for.
The EFF and other leading net neutrality proponents would probably disagree with me on "sponsored data". This is the kind of thing I was thinking of in another comment when I talked about trying to shove things into net neutrality that do not belong there. Yes, "sponsored data" favors bigger, established content providers, so could harm competition. We've got antitrust law to deal with that.
When an ISP charges a service provider to get access to their customers, they are leveraging their monopoly on those customers to extract rents from other service providers. What is the social value of this behavior?
The main problem with this line of argument is that is can be applied to anything an ISP does, because there is of course no functioning market for last-mile connectivity in most areas. A real fix would be unbundling or something else that split allowed there to be a functioning market over shared infrastructure. That doesn't mean we can't stop them from rent-seeking from other firms in the "short" term. Doing so is in line with Republicans' claimed pro-business stance.
I'm not saying Comcast should hold other video services for ransom; I'm just pointing out an oddity of the argument you're using.