A decade long development for a never before attempted interstellar cargo ship... I'm sure that "billions" is as precise as anyone can be about the cost right now.
I agree about general journalistic innumeracy, but in this case it may well be the best estimate available. It's no different from the order of magnitude estimates highly numerate people make for good reason all the time.
I'm annoyed by this innumerical journalistic habit where imprecise large numbers are only given as "millions", "billions" or "trillions".