[citation][nom]stoatwblr[/nom]$250 for 2Tb is 20% above what I pay for enterprise sata drives certified for the RAID arrays I'm using. What I'm saying is if that can be price matched then I'd change virtually everything out in a heartbeat. For the kind of workload I have (and most large data stores have), the performance specs are complete overkill and I'm more than willing to trade them off against price.[/citation]
You're not paying for SSDs with that kind of money and I thought that is was kinda obvious that I was talking about SSDs. If your workload doesn't even need a slower SSD, then HDDs seem to be the best choice and if not, then maybe hybrid HDD/SSD devices or SSD cached HDDs or some other such solution. SSDs are a waste of money if you don't make use of their huge performance advantage. Also, if you're worried about power consumption, then you could look at the Samsung 830 SSDs.
They use almost zero power (maximum power consumption is something like 0.15w and idle is below 0.1w) despite being one of the fastest SSDs for read operations. Since their performance is far from what you're looking for, a caching solution that lets them simply help out the hard drives might be considerable. However, despite being one of if not the most reliable consumer SSD, they aren't enterprise SSDs and I don't know how badly that would effect their usage by you nearly as well as I think you would. Maybe there are enterprise versions or Samsung might beat least considering making enterprise versions.
Regardless, surely you realize that there is a huge difference in cost between 2TB of HDD storage and 2TB of SSD storage regardless of the performance of the SSD. It simply isn't as cheap to make an SSD as it is to make an HDD and profit margins are even higher to compensate for that and then some.