That's not how it will play out, though. Even without network neutrality rules in-place, that would run afoul of anti-trust and consumer protection law.
The way ISPs will extract money is by nominally creating a two -tiered network. The lower tier will be the default tier. All external traffic will be routed over it by default. Entities like NetFlix will be able to pay the ISP to have their traffic routed over higher tier. The higher tier will have better latency, will be charged against an end-users throughput meter at a discounted rate, or both.
It will be a form of hidden price discrimination and thus a form of hidden tax on the market. price discrimination is usually a good thing, and even a hidden tax isn't per se bad. The reason this is bad is it will allow the ISPs to extract far more wealth from the Internet than they would ever add by improved and cheaper service.
A free market requires transparency in pricing between Alice and Bob. If Mallory can insert herself between Alice and Bob, she can obscure pricing signals. That means Bob will have a more difficult time assessing the worth of services provided him by Mallory and Alice. That also implies he'll have trouble assessing the value proposition of competitors to Alice and Mallory.
Comcast may try to extort money from Netflix, but alot of people assume that in the long-run Netflix would benefit from the tactic. They have a huge first-mover advantage. Comcast would never be able to provide a service like Netflix as well as Netflix does. The result will be that while Comcast may extract profits from Netflix, Netflix and other incumbents will have less competition and in the long-term might even benefit relative to net neutrality. Comcast will effectively provide a moat for Netflix and other incumbents in the form of higher barrier to market entrance for startups, as the incumbents will pay an effectively cheaper per-byte rate (much cheaper than in a net neutrality world) given their huge volume. Furthermore, incumbents will be a cash-cow to the ISPs, creating significant incentive to be hostile to competitors.
The losers will be consumers, prospective competitors, and overall technological and market vibrancy. But all of this will, again, be largely hidden. The solution is simple, obvious, fair, well-understood, but stark, especially in the context of a conservative narrative about regulation. It also has tons of precedent going back hundreds of years in terms of the legal and economic study of common carriers. The end-to-end principle of networks is conceptually related, too. The malady will be an obscure low-grade fever that saps value and weakens competitiveness, but will largely go ignored over time, after which people will wonder why the pace of innovation slowed down so much.