Never owned a 7D II (only mark 1) so I can't speak for the build quality, but we are in different times now and expectations are different. The 7D II came out much later than the 5D III so it's not entirely surprising that the build quality is better.Do you acknowledge that the 7D Mark II at launch was cheaper and had better build quality than the 5D Mark III? Not to mention the inferior 6D (in all but sensor size) was more than the 7D Mark II as well? An R7 for slightly less than the R6 would not be historically unprecedented compared to the history of the 7D series and the 6D series.
I'd be very happy to see an R7 class camera come in at a lower price point than the R6. Of course it's possible, and we mustn't forget that the EOS R and RP are still being sold presumably at a profit at a lower price point.
Following on from this I wonder
What compromises would be acceptable to the 7D market in order to get the price of the R7 lower?
I'm assuming that essential features would include the best weather-sealing, magnesium body, high-quality EVF, two card slots and it would certainly make sense to share the R6/R7 body shape and grip.
Would the R5 top screen be required or would the R6 dials be acceptable?
Would CFExpress be needed, or dual UHS-II?
I certainly could imagine a hybrid of R5 and R6 features with an APS-C sensor as a way of getting something at a lower price point than the R6 - but not a straight R5 with an APS-C sensor.