The “Women of Belfast” sculptures, created in the 1970s, were inspired by the victims of a bombing at the Abercorn Restaurant in Belfast in March 1972.
Ms Molenaar said “The figure we sold portrays a woman fighting to remain standing, her head bowed, limbs at unnatural angles and her clothing blown forcefully backwards by the sheer force of the explosion.
“The significance of these sculptures is no less poignant today, exemplifying the innumerable innocents caught up in modern conflicts worldwide.”
Both the seller, described as a Midlands art collector, and the Welsh buyer declined to reveal their identities.
The winning bidder in Wednesday’s auction saw off rivals from Ireland and Italy to secure the purchase, the auctioneers said.