Collectors will need more than a "heart of glass" to compete for a portrait of Debbie Harry when it goes to auction this month.  Sotheby's is marketing a print by the late Andy Warhol that features the Blondie singer.  The auction's scheduled for this June 11th in London.  Experts say the Debbie Harry silkscreen should attract over eight-and-a-half million dollars.  Harry posed for Warhol at The Factory in New York in 1980.  Debbie says she was flattered to be Warhol's "muse."  She has joked that it's put her in the company of Elizabeth Taylor and a can of Campbell's soup.