There are four hidden costs which not many have touched upon. 1) Staff You'll need at least one, maybe two, to build, operate, and maintain any self-hosted sol

There are four hidden costs which not many have touched upon. 1) Staff You'll need at least one, maybe two, to build, operate, and maintain any self-hosted solution. A quick peek on Glassdoor and Salary show the unloaded salary for a Storage Engineer runs $92,000-130,000 US. Multiply by 1.25-1.4 for loaded cost of an employee (things like FICA, insurance, laptop, facilities, etc). Storage Administrators run lower, but still around $70K US unloaded. Point is, you'll be paying around $100K+/year per storage staff position. 2) Facilities (HVAC, electrical, floor loading, etc) If you host on-site (not hosting facility), you'd better make certain your physical facilities can handle it. Can your HVAC handle the cooling, or will you need to upgrade it? What about your electrical? Can you get the increased electrical in your area? How much will your UPS and generator cost? Can the physical structure of the building (floor loading, etc) handle the weight of racks and hundreds of drives, the vibration of mechanical drives, the air cycling? 3) Disaster Recovery/Business Continuity Since you're using S3 One Zone IA, you have no multi-zone duplicated redundancy. It's use case is for secondary backup storage for data, not the primary data store for running a startup. When there is an outage/failure (and it will happen), the startup may be toast, and investors none too happy. So this is another expense you're going to have to seriously consider, whether you stick with S3 or roll-your-own. 4) Cost of money With rolling-your-own, you're going to be doing CAPEX and OPEX. How much upfront and ongoing CAPEX can the startup handle? Would the depreciation on storage assets be helpful financially? You really need to talk to the CPA/finance person before this. There may be better tax and financial benefits by staying on S3 (OPEX). Or not. Good luck.