AWS EC2 Spot Instances

My major complaint about using EC2 GPU instances was the cost, it gets very expensive to run a GPU instance for more than a few hours. Last week I was wondering why I wasn't using spot instances, so I set up a request and I've been running it for a few days now. It is about 1/4 the price of a normal instance, so it's not much more expensive than renting a CPU-only on-demand instance. I was hoping to get a better GPU than the K80, but I ended up settling for the K80 because it was more available than the better GPUs, but next time I may request a better one and see what happens.

The downside of spot instances is that they will be terminated if the capacity is needed for an on-demand instance, and my instance was terminated the other night. But then I spun up a new one in the morning and that one has been running for a few days now. I can't believe I haven't used these before.