As our troubled age becomes ever more gilded, art auction prices soar with bone-numbing regularity. A new high-water mark was reached on Tuesday, when a 1969 triptych by the British painter Francis Bacon sold for $142 million while the Christie’s auction in which it was featured took in $692 million. Both figures exceeded recent highs: One arrived in spring 2012, when Edvard Munch’s “The Scream” sold for $119 million at Sotheby’s; the other came last spring, when a Christie’s auction total reached $492 million. It seems that people really, really like art these days.