The selling price for a major portion of La Habra Fashion Square was less than $10 million, Steve Hopkins, president of Hopkins Development Co., said this week. The Newport Beach development company plans to transform the mall, historically one of the county's poorer performers, into a high-volume center anchored by mid-priced, promotional stores. Hopkins must negotiate to buy the sites of the two existing anchors at La Habra Fashion Square: Bullock's and Buffums. The Bullock's store is owned by the chain's corporate parent, Federated Department Stores. Buffums is owned by Los Angeles-based Gilbert Investments. A previous report had the 14 acres of the 37-acre mall being bought for less than $14 million.