We actually used to use Samsung EcoGreen drives in order to get more storage for cheaper, since our main use was backup: write once, read maybe. Unfortunately there don't exist 5400RPM 3TB drives; if they were as cheap as the 3TB Seagates, we'd buy them for sure. The 5400 rpm Ecogreens used to be the cheapest 2TB drives on the market by a large margin.
I never expected that paying more for a slower drive (but better power and less power-related issues) would actually make sense!