The last time I did the numbers on reserved instances, I was initially surprised (and subsequently not surprised at all) to find that the present value cost of

The last time I did the numbers on reserved instances, I was initially surprised (and subsequently not surprised at all) to find that the present value cost of reserved vs payg was close to identical assuming a typical A- rated corporate debt rate. Given that my cost of capital is higher than Jeff's but my inherent risk (in demand i.e. workload predictability) low, it made sense to go reserved.