Many people prefer to pay extra for peace of mind.

What isn't clear is if some people pay extra for a second key.

You pay extra for the one that does 3G as well.

Tell you what, I'm not even going to charge extra for those services.

I use what I've got, unless people want to pay extra for something special.

If I have to pay extra for this then so be it.

She has also served as an extra for the show.

If a few people want to pay extra for the privilege, why not?

You are simply paying extra for a very firm bed.

It's well within what people might be willing to pay extra for the system.