An AVX-512 Skylake-X cloud compute instance costs $10 per CPU-core per month at Vultr (https://www.vultr.com/products/cloud-compute/), and you can do about 18 DenseNet121 inferences per CPU-core per second (in series, not batched) using tools like NN-512
GPU cloud compute is almost unbelievably expensive. Even Linode charges $1000 per month, or $1.50 per hour (look at the GPU plans: https://www.linode.com/pricing/#row--compute). It's really hard to keep that GPU saturated, which is what you need to do to get your money's worth
As AVX-512 becomes better supported by Intel and AMD chips, it becomes more attractive as an alternative to expensive GPU instances for workloads with small amounts of inference mixed with other computation