Oxford Properties Group, a global real estate investor, asset manager and developer, announced it accepted a surprise offer from biotechnology company Moderna, Inc., to buy a newly built, 140,000-square-foot GMP facility named the Marlborough Discovery Center at 149 Hayes Memorial Dr. in the Boston submarket of Marlborough, Massachusetts, for $91 million, or a whopping $650 per square foot. No brokers were reported to be involved in the owner-user sale.