A new breed of AI assistant has set its sights on the enterprise user in recent months, with Microsoft and other vendors promising huge productivity gains that offset the cost. But Microsoft still has work to do on its value proposition. Its Copilot for Microsoft 365, a high-profile offering among the growing list of AI agents, costs $30 per seat per month, with a 300-seat minimum. The enterprise version of Gemini, Google’s AI assistant, is similarly priced. Price is a big reason why the University of California, Riverside, is hedging its bets and evaluating several AI tools, says Matthew Gunk…