If you're confident in the soundness and security of your proposed system, then it's certainly possible to set up five servers in an insulated commercial space using a fluid-based cooling system.

Based on your estimate of $10,000 per server and $60,000 for additional modifications to the building or space, the total initial investment would be around $110,000 - $120,000. Keep in mind that this is just an estimate and actual costs could vary depending on various factors such as hardware availability and pricing.

It's important to carefully consider all of the potential costs associated with cryptocurrency mining before making any significant investments. Additionally, make sure that you have a solid plan for ongoing maintenance and upkeep of your equipment to ensure its continued reliability over time.

Overall though if you believe in your idea and are willing to put forth the necessary resources it could potentially be a worthwhile investment opportunity!