Fast and inexpensive storage
While my capacity needs are better served by 4TB drives, the 3TB ones are very fast and a much better deal on a dollars-per-gigabyte basis.
Fast PCIe SSD
Prices on the OWC Mercury Accelsior PCIe SSD (what I use for my work every day since it arrived) have also dropped slightly, to $447.50 for the 240GB model and $699 for the 480GB model.
The Accelsior can be used directly in the Mac Pro, or with any Thunderbolt Mac by installing it in the Mercury Helios case.