Hi,
Colloquialisms vary by country. I think some British persons might informally say 'It cost 200 pound'. However, I don't think a North American would ever say 'It cost 200 dollar'. He might, however, say 'This is a 200-dollar suit', using the phrase '200-dollar' as an adjective. Perhaps it is this adjectival kind of use that Anthon has heard?
Best wishes, Clive