Not sure what you mean with "datacenter". If you mean using co-location or similar it probably works out as a small price difference. If you start with an empty room or an empty piece of ground it might cost you a lot to start building everything and hire people to manage it all. Remeber that the big cloud providers can get a scale benefit where a lot of virtual computers share a small operations team. I do think that physiccal servers usually are faster than cloud computers meaning you might be able to use fewer of them to compensate for the price difference.