I was talking about a different sort of flexibility. The ability to spin up another instance identical to this one if you suddenly need more capacity. The ability to spin up instances to do some data crunching, then turn them off when done, so you only pay for what you use.
If the capacity you need is fixed and known it will be cheaper to get a dedicated server. Here's a a counter example. I once worked for an online retailer and we got an order of magnitude more traffic at christmas. With a dedicated server we had to pay for the capacity needs of christmas all year. On the cloud we could add capacity for xmas and then turn off hte extra capacity the rest of the year. It was a lot cheaper.
If the capacity you need is fixed and known it will be cheaper to get a dedicated server. Here's a a counter example. I once worked for an online retailer and we got an order of magnitude more traffic at christmas. With a dedicated server we had to pay for the capacity needs of christmas all year. On the cloud we could add capacity for xmas and then turn off hte extra capacity the rest of the year. It was a lot cheaper.