Is there a standard for speaking "1500" as "one thousand five hundred" versus "fifteen hundred"?
Solution 1:
One thousand five hundred is more formal than fifteen hundred. Both will be understood by the listener and are correct English, but one thousand five hundred would be more appropriate on a legal document such as a contract.
Also, in an informal setting, such as when talking about sports statistics, people may look at you funny if you use one thousand five hundred rather than fifteen hundred.
Solution 2:
Quinze cents is more common in French than mille cinq cents.
I tried COPA, but could not get a search done as to usage. I think/wonder if our use of one thousand five hundred relates to how it is usually written: 1,500 vs 1500. Perhaps because of my science background, I think in 'hundreds'. But I hear *one thousand five hundred* more commonly when referring to something other than money, even though banks prefer one thousand five hundred on a check.
Googling, I turned up three times as many hits for one thousand five hundred than fifteen hundred.
Nothing unequivocal, I'm afraid.