You can calculate the amount of rewards you could possible receive by running a DAG Validator Node using this spreadsheet created by Ekthelius the Accumulator. It is based on information we currently know about Nodes 1.0. It may not be completely accurate for Nodes 2.0 and does not take State Channels into account. But it should give you a good idea of how Nodes calculate rewards. You just need to input the amount of nodes running as a DAG Validator Node and the token price at the time. Remember, the token value will be much higher with the amount of Nodes that are purchased and Nodes 2.0 opens up State Channels that all have their own rewards pools that Node Operators can choose to be on. So not every Node would be collecting from the same reward pool.
DAG Node Speculative Income Calculator:
https://t.me/ekthelius/1085