In Australia it's very common to say 'the presents were dear' meaning expensive. Is this used in UK/USA as well, and/or accepted as a translation?
In the US, I would have to say No. I have read it in (foreign or maybe old fashioned) novels, but never heard it. I would be more likely to think they meant the presents are darling, or adorable.
In England, I'd understand it, but it sounds old-fashioned. (Might be more current in some parts of the country than others.) It was familiar enough to be useful as a mnemonic for dyr, though.
It's common in the UK as well, at least. I respectfully disagree with butsuri here.
Both mean "expensive", but dyr is in the sense that you don't like the cost of something you buy, and dyrbar is in the sense of precious, or valuable.