Extended Warranty Good Idea on Used Prius?

everyone. I apologize if this has been covered thoroughly elsewhere, but I am a newbie, newbie Prius owner (as in less than 24 hours). Normally, I am an extremely methodical researcher when it comes to things like (1) expensive purchases and (2) extended warranties, but I am embarrassed to say I was caught short at the dealer last night when they offered me the warranty. I've already called them to say I'm going to cancel it because I'm thinking it's just not worth it in my particular case, but was wondering if any of you would have an opinion. Here's the situation:

(1) It's a 2005 Prius with 46,000 miles on it, one previous owner. Obviously lots of driving in those two years. This is a Toyota Certified Pre-Owned, so am assuming/hoping (might be a mistake, though this dealer has an OK reputation) that it's in good shape. The basic Certified warranty is just a 3 month/3,000 mile, and the standard 100,000 mile powertrain warranty continues until 100,000 miles.
(2) My understanding is that you can get the Toyota Certified Platinum Warranty on a used Prius that is beyond the standard 3 yr/36,000 warranty period only when you actually purchase the vehicle, so if I were to do this, now is my chance.
(3) The price they charged was $1,930 (yes, I know, I know). They will come down, however. They do tout the "buy back" feature of this warranty (as in, if you don't use it, you get your $$$ "back"), but as we've seen elsewhere in this forum, that's kind of meaningless. This is insurance. It is a risk.
(4) Barring some sort of lemon issue or something, I will keep the car forever (the car it is replacing was 17 years old). I very likely would not resell until it's worth almost nothing.
(5) Here's the clincher: The warranty only covers you to 100,000 miles on the vehicle. This means total vehicle miles, not 100,000 miles from when you buy the warranty (that's where they misled me and where I now feel like an idiot).

So, on to the question: Does it seem stupid to buy an extended warranty for what is basically going to be 54,000 miles of driving? We will put 15,000 on it a year, mix of town and highway. We take very good care of our cars in terms of maintenance and whatnot. My gut says that it's ridiculous and I would like to think that Toyota reliability will be good here, but at the same time, it is my first hybrid, and I will admit to being a touch worried about extra large repair costs if something really does go wrong.

Thanks for any input!