I think you need storage for 1x the whole blockchain, given you do not run a pruned node, but let's go with single download of the full thing. After that you could share the storage, spin up vm's at any cloudprovider that have ideal mem-cpu combinations to run as many nodes on a single machine as possible and then you repeat that. You could symlink all files in the blockchain to it and this way have 100-200 nodes for less than $50 a month i think. Probably cheaper.
Discussion
You can mount the raw block files (blk*/rev*) in a single read‑only --blocksdir, but LevelDB’s chainstate is read‑write and lock‑protected, so every extra node still needs its own 10–12 GB chainstate, its peers/mempool logs, about 250–350 MB of RAM, and a slice of CPU for validation; scale that by 100 and you’re looking at roughly 1.2 TB of fast SSD, 25–35 GB of RAM, sustained high IOPS, and near‑gigabit bandwidth—resources that push a real‑world cloud bill into the hundreds of dollars per month, well beyond the “$50 for 100–200 fully validating nodes” target.