Rumors are swirling that Ben Affleck and Jennifer Garner are engaged to be married. According to People, Affleck popped the question over the weekend during a lavish 33rd birthday party thrown for the Alias star. He reportedly sealed the deal with a 4.5-carat diamond ring from Harry Winston valued at $500,000 — roughly half of what he spent on Jennifer Lopez's 6.1-carat rock in 2003. For those keeping score at home.