There are three sources of revenue for a validator.
**Inflation:** Solana has a predefined inflation schedule. Any staked Solana participates in this inflation, unstaked does not (need to verify). The validator gets to collect a percentage of the delegated stake. This percentage is referred to as commission. The validator can change their commission rate at any time and can range from 0% all the way to 100%
**Transaction Fees:** When the validator is the leader theyget to collect the transaction fees generated by the network activity during that leader slot. The more delegated stake you have the more often you are the leader. It is possible to break even with 0% commission from transaction fees alone. need north of 700k Solana for this to work.
**Storage Rent Fees:** Like transaction fees storage rent is given out to leaders during their slot. All rent is collected at the beginning of an Epoch and is paid out as the leaders are voting on and processing transactions. The income from this source is also a function of the leader slots the validator is scheduled for and are therefore dependent on the total delegated stake.
Transaction Fees: Solana is unique in that voting is done on chain and the votes themselves cost the same as any other transaction. This ends up being the primary cost of running a validator. It cost roughly .8 sol a day to run a well performing validator. At current prices that ends up being around 54k USD a year
Server Costs: Server costs are the next mostsignificant expense you are likely to face. Depending on your DC you are looking to spend at least 500-1,000 USD a month on your primary server. If you are working for the Solana Foundation Delegation program stake then you will have to have 2 servers. One for mainnet and one for testnet. Solana offers a reasonably easy way to get started with a Solana ready server through their Server program. You can expect to spend ~$600 a month with their best options.
Bandwidth Costs: Solana Validation is a very bandwidth intensive use case and data centers that charge by the gigabyte of in and out traffic are likely to get expensive quick. It is reccomended that you consider Bandwitdh costs along side server costs when choosing a hardware provider. Cloud providers such as AWS can easily double in cost after considering bandwidth. Many of the options through the Solana Foundation server program also include bandwidth