What's a suitable price tag for a royal wedding gift? [Poll]

Kate Middleton and Prince William have famously asked their wedding guests to donate to some favorite charities instead giving the royal couple gifts off a registry.

While that is generous and practical (what do you get a prince anyway?), can a guest really show up empty-handed? And either way, how much should a guest spend? We asked an expert:

"Typically when people are invited to a wedding it does involve travel and airfare and expenditures," says Lisa Gaché, manners expert and chief executive of Beverly Hills Manners. "For this kind of a wedding -- for any kind of a royal wedding -- it is considered a great honor. In order to show or convey respect and that gracious feeling for being invited, the ante is a bit more."

Gaché would put the sticker price at $500, what she called "a nice investment while not breaking  the bank." Or, she says, you could get off a little cheaper by giving a gift with a personal touch.

"I just read that as a gift, George Michael is performing a song for the happy couple and that there is also a Royal Wedding Charity Fund. ... [T]hese two types of gifts fall under the category of getting to know the couple and presenting them with a special gift they would truly enjoy," she said.

"If you cannot offer something creative and unique such as a live performance, then the charity option is an excellent opportunity for guests to contribute their support monetarily. In this case, I believe a $500 donation would be considered generous."

Do you agree that $500 is an appropriate gesture in honor of Kate and her prince?

RELATED:

A who's who guide to Prince William and Kate Middleton's crowd

Royal wedding memorabilia: Owning a slice of Prince William and Kate Middleton's big day

Interactive: Your guide to the royal wedding

-- Whitney Friedlander

Photo: Prince William and Kate Middleton, photographed soon after their fall 2010 engagement. Credit: Mario Testino / AFP / Getty Images