Where, roughly, would one look for an "average or below" entry point for equal weight indexes like RSP or QQEW?

One of the joys of Berkshire is that its valuation range has historically been pretty narrow and predictable : ) S&P 500 companies, less so.
So one can comment on RSP's valuation level relative to history, but it doesn't really tell you much because nobody has much of an idea what the valuation level will be in the next decade.

But I have tried it with QQEW, which oddly seems to be more predictable, at least historically. The gyrations are wild, but they average to a predictable line.

I built a trend line of the average (actually median) real earnings over time, which has so far trended extremely well except for dips in recessions. Then I look at the long run average earnings yield expressed as that real trend-earnings level divided by the current real price, to come up with an "average" valuation level, and bravely call that fair value.

A while back I estimated that QQQE was maybe on the order of 10% more expensive than usual, May 28 last year, and that value had historically risen at around inflation + 8%/year (not counting the usual .5%/year dividends). mungofitch replies on What’s the better value rn, brk or qqqe?
The price return since then is pretty similar to the historically typical trend value gain, so the valuation level is probably in the same vicinity: a bit high but not painful.

I would do an accurate update for you, but it's quite a long calculation!

My comments from that post may still apply, comparing Berkshire and QQQE:
"A valuation that's richer than usual by 10-20% isn't nearly enough to say "you'd be a fool to deploy your capital now, you really oughta wait". Since both are safe and growing in value, likely the worst case for the long run is just a flat spot for a while, with uncertain timing. That being said, my gut feel is that within 12-18-24 months both of these will be available at valuation levels that are at least somewhat cheaper than average rather than more expensive than average. But it's not usually a good idea to base investment decisions based on the gut feel of some rando on the internet."

The main change since then is that Berkshire's price has risen a lot more than that of QQQE. So the relative attractiveness question may be hard to pin down one way or the other then and now, but it has apparently shifted somewhat in the direction of QQQE and away from Berkshire since then.

Jim