May be OP still can go for AWS or other cloud services and fetch the data for open source purposes. They have various options available and plus its always costly when you build up your own server. Hardware server specifically are very rough to manage.
Oh yeah, that was what I'm referring to. I thought that was what OP meant in the first place, not building his own network and maintaining it on his own. If he wants to do that, I guess it really depends on his budget.
And, if the accuracy of such simulator is very well then I think it can be a sellable piece of software, and the whales might pay you for such simulator without rethinking.
I doubt they would base their trading decision on a prediction from a software that has limited backtesting/data though. I believe OP is also aware of that, hence why he plans on adding new features in the future. He can definitely ask for a monthly/yearly plan as long as the features are in demand, but I doubt he'd be able to sell the code to other companies that easily. CMIIW.