When you see the price of the dual GPUs, the ECC RAM, PCIe SSD, and the small design, you will see why they didn't toss in the warranty for free. You do get 1 year free warranty though and that's something. It's only $249 for the extra two years which is worth it in my opinion.

ECC isn't that much more expensive, while AFAIK the price premium for pro-model GPUs is almost pure price-gouging, and Apple's surely not paying those inflated prices for the GPUs.