Examples of some of the deals I’ve personally gotten (ymmv, some were auctions):

• 5 x 3.84TB SAS SSDs
  • $521.54 total (stunning deal, I got lucky)
  • $104.31/drive
  • $27.16/TB
• 5 x 960GB SAS SSDs
  • $165.17 total
  • $33.03/drive
  • $34.41/TB
• 7 x 12TB Toshiba SAS HDDs
  • $427.31 total
  • $61.04/drive
  • $5.09/TB
• 2 x 8TB Seagate SAS HDDs
  • $49.99 total
  • $25/drive
  • $3.13/TB
• 2 x KTN-STL3 JBODs each including 15x3TB SAS HDDs
  • $532.73 total
  • $266.37/shelf
  • $17.76/drive bay+drive
  • $5.92/TB not including value of JBODs (~$150/each without drives)