Question: Why do the bigger name brand storage arrays cost so much?
Answer: A lot of what you get with the storage arrays from the larger companies is more features. The newer players to the market offer a storage array but some times they have only the most basic features. Features like snapshots, clones, replication, consolidated backup, VDI integration with VMware and Hyper-V, etc. are simply not there.
If all you need is basic storage and you want to be able to work with your storage array as if it was a large consolidated DAS unit then these features which aren't available may work just fine for you. However if you plan on doing site to site replication at the storage array level, or you want to take snapshots and present those snapshots are writeable LUNs to another host then these less expensive arrays may not work out for you as they don't support these features.
When selecting the storage platform that you want to use it is very important to fully understand all the features that you are looking for today as well as tomorrow. If you don't know all the features that you are looking for then you may end up purchasing an array that doesn't do everything that you will need it to do.
As with any large purchase do your research, at least twice, to make sure that you are getting exactly what you need. Purchasing the wrong storage array is a very expensive mistake to make as moving data from one array to another is typically a hard and expensive process to go through, with a lot of down time.