Well I paid £1150, for my Merc. And it was more than I wanted to pay (£600-800) for a high end card. But in this market, and with prices creeping up in January, it was take it, or leave it... And I know it'll last 2-4 years, and get used everyday for solitaire.
As for my RAM, I am running:
G.SKILL F4-3600C17Q 64GTRZ
So that's 4x 16GB. I am running it in XMP mode. So Infinity Fabric is at 1800MHz. But not tried to push it beyond that, or forced the timings to be tighter.
I know it's overkill for gaming, but I keep 10 Chrome Tabs open, and can have lots of apps open for analysis, which are memory intensive. Usually these are closed for modern AAA games, which use the CPU, RAM, and GPU extensively.