The Malden Redevelopment Authority will hold a public meeting Thursday to discuss two proposals to redevelop the Emerson School. The meeting is set for 7 p.m. at the Highland Avenue school. One developer, the Traggoth Companies, offered $127,500 in cash to preserve the outside structure while converting the interior into six condominium units. The other offer came from Mystic Valley Charter School, which said it would pay $1.3 million for the building and spend $1.5 million more in renovations to use the space as overflow for its high school. The charter school offered ancillary perks, including opening the building once a month to artists and maintaining a World War II memorial. The condominiums would add an estimated $14,500 to $25,000 to the property tax rolls, according to the redevelopment authority.