The screen is costly, yes. But so is flash storage. I opted for the 1TB. You can get a 1TB Samsung EVO 850 Pro for considerably less, albeit at slower 6G speeds too. Then again, you pay a premium for 64GB of flash on iOS devices even though super fast 64GB thumb drives sell for much, much less than what Apple charges.
Regardless, I do not regret the purchase of this late 2015 5K iMac. I hope the benchmark results help those of you still mulling a purchase.