Things are moving fast on the NBI Inc front, and now Capital Associates Inc of Colorado Springs says that it is prepared to offer $7 a share for all outstanding shares of the Boulder, Colorado word processing systems firm. NBI is already under fire from Fisher Investments, which has about 7% of its shares. NBI shares were trading at $6.25 on the New York Stock Exchange ahead of the announcement. Capital Associates, a leaser and broker of high technology equipment, says that it talked with NBI in February about buying some of its businesses, but got a dusty answer from the firm.