Perezhilton.com reports that just three weeks ago Carmen sported a black diamond engagement ring on her finger, but when she discovered that the ring costs less than $2,000, she got upset.

“She seems really embarrassed. I think the ring is a real deal breaker. She thought she’d be getting this giant rock. Instead, Rob bought it online for a bargain price,” said an insider.

The insider added: “Rob doesn’t have a lot of money coming in and he’s been driving around in Carmen’s car while she’s working. He’s a total freeloader. Carmen’s starting to realise that Rob may not be able to hold up his end of the bargain.

“They aren’t breaking up tomorrow. She’s shooting the movie Goodie Two Shoes in Louisiana and has lots of appearances lined up, so she and Rob won’t be together that much. The less time they spend together, the longer the relationship will drag on, but it won’t last. She’ll come to her senses.”

A source close to the couple has told Hollyscoop exclusively, “The wedding invitations have been sent out, its taking place the weekend of May 16. The location will not be revealed until the day of the wedding but guests are told it will be an hour drive from Los Angeles.”