The other big issue people usually don't mention or consider when discussing dedicated hardware is that not only will it take longer to add capacity, but it is also a risk every time you add servers you risk the entire network that server is being added too. Unlike a cloud environment, adding servers to a dedicated environment is not necessarily going to be as well practiced - so errors are more likely... These types of errors are pretty bad too e.g. All servers offline kind of bad. We had this happen two very bad days followed and now I can only recommend aws with reserved instances and multiple regions.