Delta seems to have "quietly" devalued their redemption "chart". A year ago I got a business class round trip USA<->Europe for 125k (62.5k one way), and just months ago I saw posts on people getting the same redemption rate. But now the third-party-generated Delta chart shows it's 140k round trip (70k one way):
and some checks on Delta's web site for the same route I flew earlier this year (but reserved late last year) for 125k round trip show the same thing, "lowest price" being 140k round trip.