Steve Streza describes his storage system in My Giant Hard Drive: Building a Storage Box with FreeNAS.
At his prices, about $136/TB for 11 TB of storage.
Large enough for realistic simulations of data mining or topic mapping. When you want to step up to production, spin up services on one of the clouds.
Not sure it will last you several years as Steve projects but it should last long enough to be worth the effort.
From the post:
For many years, I’ve had a lot of hard drives being used for data storage. Movies, TV shows, music, apps, games, backups, documents, and other data have been moved between hard drives and stored in inconsistent places. This has always been the cheap and easy approach, but it has never been really satisfying. And with little to no redundancy, I’ve suffered a non-trivial amount of data loss as drives die and files get lost. Now, I’m not alone to have this problem, and others have figured out ways of solving it. One of the most interesting has been in the form of a computer dedicated to one thing: storing data, and lots of it. These computers are called network-attached storage, or NAS, computers. A NAS is a specialized computer that has lots of hard drives, a fast connection to the local network, and…that’s about it. It doesn’t need a high-end graphics card, or a 20-inch monitor, or other things we typically associate with computers. It just sits on the network and quietly serves and stores files. There are off-the-shelf boxes you can buy to do this, such as machines made by Synology or Drobo, and you can assemble one yourself for the job.
I’ve been considering making a NAS for myself for over a year, but kept putting it off due to expense and difficulty. But a short time ago, I finally pulled the trigger on a custom assembled machine for storing data. Lots of it; almost 11 terabytes of storage, in fact. This machine is made up of 6 hard drives, and is capable of withstanding a failure on two of them without losing a single file. If any drives do fail, I can replace them and keep on working. And these 11 terabytes act as one giant hard drive, not as 6 independent ones that have to be organized separately. It’s an investment in my storage needs that should grow as I need it to, and last several years.