I'm going to weigh in on this. A couple of thoughts:
(1) Like anybody in business, a lot of the hostile posters on here are lashing out because they have been burned or had their time wasted over time by customers who have put them in a position where they didn't make much money on a job. Understood. Been there. But the original poster should understand that he has become a lightning rod for a lot of folks, based on assumptions they are making about his motives and what his arrangment was with the contractor.
(2) No doubt the poster got a higher-quality result than if CPVC had been used -- likely a much-higher-quality one. (Assuming it was installed right, which I assume it was because the contractor was using a familiar material rather than an unfamiliar one.) In some sense, the contractor did "do him a favor", but it's not really a favor because the contractor charged him for it.
(3) How this would come out in front of Judge Judy would depend upon a number of facts which we don't have in this case. I would want to know what was the agreement with the contractor about what work would be done, how much it would cost, and what materials would be used? It sounds like this was a time and materials deal, but I am assuming that the contractor AGREED to use customer supplied materials. I'm not clear how it is that the client went and bought CPVC. Did the contractor say he would use that material, and then couldn't figure it out? Did he say, "Get me 50 feet of 1-inch pipe" and the homeowner went and bought CPVC instead of the copper the contractor expected? There's some sort of disconnect here, and what the understanding was between the folks is going to determine how Judge Judy would decide.
(4) Anyone who would recommend that the contractor go "rip it out" shouldn't be a licensed anything. Try to invade my home without authority and you could end up in jail or the hospital or both, before the lawsuit I would drop on you would mean I get your work van and tools.
(5) Note the term "contract" in the word "contractor". The contract between these two, oral or written, would/should have covered what materials would be provided and by whom, and what the charge for installation would be. If the contractor knew he was expected to work with CPVC and that it would be provided by the homeowner and the homeowner provided what was expected, it's one outcome. If there was a different arrangement, then a different outcome. People have a right to ask for a less-expensive, lower-quality product. If someone asked for an Original Drake, Terry wouldn't just show up and put in a Neorest and expect the homeowner to pay him the full price of that product just because it's "better". On the other hand, if the type of toilet wasn't specified, most judges would apply a rule of reason.
(6) Regardless, in the execution of any contract, communication is paramount. People can and should be able to work things out by phone, email, etc., and it's much better (and often required) that you get approval to make a change if you expect to be compensated for it. In a real AIA contract, changes require a change order. They are a pain, but the very best commercial contractors demand them every single time, regardless of whether the client rep is screaming that this problem needs to be solved now and they'll paper it later. That is a huge trap that many have fallen into, and most of the time the client rep isn't to be trusted.
(7) No reason for the homeowner to be all huffy and threatening. Same for the contractor. Something unexpected occurred. There's an amount of money that should satisfy both, or equally-dissatisfy both. Life is too short. Assuming that both sides acted in good faith, they should figure out what is fair, based upon the circumstances, exchange that money, shake hands, and move on to do more stuff in the future.