At least for newer SATA tyoe drives, you can easily remove them from a FW enclosure and drop them in a USB 3 enclosure or HD docking station.
The good news is that USB3 drive are very inexpensive. You can get 3-4TB drives at Costco or Sams for $100-129 range. You can even get a Seagate 6TB drive for $299.
Yea well problem are those old Lacie D2 Quadra 500gb Firewire/Usb2 drives. Just complete nonsense to keep those on a nMP