Scuttlebutt around 1990-ish was that, when acquired for the G'bg Park, they went for five figures (24-26K, IIRC). (Tax deductible?)

While lacking the provenance of the tags, there is a rare Union Signal Corps officer's battleflag with all five points of the star inscribed featured in the American Civil War exhibit at the National Cryptologic Museum, Fort George G. Meade, MD (NOT the Post museum, but alongside NSA).