Richard Westwood-Brookes of auctioneers Mullocks, in Shropshire, said he believed it was a "world record figure" for a letter by the Indian leader.
BBC: Gandhi letter
2.
Mr Westwood-Brookes of Mullocks Auctioneers in Ludlow, Shropshire described the document, being sold on behalf of a private seller, as "a truly historic find".