Waiting a year potentially opens up a cheaper/sooner ram upgrade path for me down the road, is my reasoning.
You aren't waiting a year. You are waiting 18 months if all things go smoothly... Don't know how much RAM you need, but it costs $70 to get a decent speed 16GB, which is all you need for gaming. The launch prices of DDR5 will be inflated and premium.
To recap:
• You are delaying your build for 18 months
• 16GB RAM costs $70-80
• Your reasoning is that 6.5 years down the line, you will not have to re-buy RAM for your next-next build
I remember watching a documentary about some hoarder who would rather burrow through trash all-day instead of working, "saving" money on food where the "stupid" people paid money for it.