Extensive studies performed by Enterprise Strategy Group (ESG) as contracted by many companies, both cloud based and hardware vendors, have revealed what many consider to be a surprising outcome. The 5 year total cost of ownership (TCO) is less for installing on premise storage hardware than when contracting for public cloud facilities.
These studies take everything imaginable into account, to include the cost of storage capacity, maintenance, support, power consumption, cooling, the cost of capital and storage administration.
The TCO difference is greater in circumstances where data security compliance is in the mix. An example is a medical environment in which HIPPA compliance is mandatory.
The bottom line is . . . well . . . the bottom line. Yes, the entry cost of plopping your data onto a public cloud certainly looks attractive as compared to establishing an on premise hardware installation, but over time, hang onto your wallet.