But the thing is I am not sure if amazon keeps a spot-instance reserve (i.e. what happens if all the spot instances get turned into on-demand ones over, say, a month and suddenly your service is shut down and you keep waiting indefinitely[you'd probably wait for around 24 hours and then try to get an on-demand one - which is 11x more expensive, costing around $600/mo for a shared gpu. and if you can't find an on-demand one, you will be offline for around a week until you figure out a way of provisioning a gpu instance from another service provider, which will probably cost you a lot more, but at that point you will have to do it not to disrupt the service for so long])
But the thing is I am not sure if amazon keeps a spot-instance reserve (i.e. what happens if all the spot instances get turned into on-demand ones over, say, a month and suddenly your service is shut down and you keep waiting indefinitely[you'd probably wait for around 24 hours and then try to get an on-demand one - which is 11x more expensive, costing around $600/mo for a shared gpu. and if you can't find an on-demand one, you will be offline for around a week until you figure out a way of provisioning a gpu instance from another service provider, which will probably cost you a lot more, but at that point you will have to do it not to disrupt the service for so long])