Good point, since it would be a different chipset. Nice catch.
Either way, I don't really think DDR4 is all that important, especially right now since it's so new. Unless you're doing high memory intensive things the improved throughput might not be worth it.
Anyways, if you want DDR4 there's still >100 bucks of leeway to upgrade the MB, RAM, and CPU.
No point in getting a gold PSU unless it's also cheaper imo. It doesn't actually affect performance.
I was using amazon pricing, but I might have added wrong LOL