Is ddr 4 worth it?

Hi, I’m building my own workstation.

Recently I got a 1080ti cheap (I know I should wait till the end of the month but the deal ws soo good). Being a person who used servers all his life, I don’t have a workstation to use this thing on.

I’m mainly looking at the Xeon line of CPUs and a set of CPU, motherboard, ram for ddr4 costs significantly more than an equivalent one with just ddr3 (it is also an earlier version of the same xeon CPU)

I’d mainly be using the workstation to train detection and siamese networks.
Is a saving of $400 usd worth it?