Interesting question.
So think 400kwatt not 500.
Rugged immersion setups would be very niche.
But 100 air cooled s19s are cheap maybe 40k
they would do 10ph which is 300 dollars a day so in 150 days you have 45k.
the s19s would be fairly disposable since they are cheap.
Immersion is a costly setup. You need good fluids which cost and large tanks which cost.
You need to watch the pumps. When a pump goes a tank will over heat really fast.
You could lose a lot of miners fast.
https://www.ebay.com/itm/227160694575?you should contact the seller above as he does have a lot of equipment for immersion.
you could kick over ideas with him.