I believe we already have some hints from Ethereum 1.0 mining statistics (or BTC). Current Ethereum 1.0 has 176.06Th/s, and consider just 1/1000 hashpower as a threshold to join a pool or mine solely by running a full node, the corresponding cost of mining will be (using 1070Ti with 30.5 Mh/s with about 500$ in Amazon)
- Equipment: 176.06 Th / 1000 / 30.5 Mh/s \approx 5772 graphics cards, which is about $2.8M (using other devices may be lower, so let us use $1M as a conservative number)
- Electricity: Suppose the miners get 50% profit from Ethereum mining, then the electric cost of the 1/1000 miner will be 365 * 24 * 3600 / 1.35 (block time) * 2 (Eth per block) * 180 (Eth price) / 1000 = $0.84M
While running a super-full node in a cloud for 1024 shards should be on the order of $0.1M per year.