Dear Experts: We are interested to purchase the storage from netapp FAS 2020 (SAS disks 300GB*12) we are about to issue purchase order but only now we got to know additional shelf for this model available is 1TB*14 drives of SATA and this will cost more than the product, due to this we are not able to go for this. Reason for not going for this is if we purchase this then total raw space is of capacity 3.6TB and usable space will be only 2.4 TB. If it would have been 600*12 then I would have gone for this or if additional shelf comes with 300*14 it would have worked out to be lesser than the product cost. Please suggest me is there any alternate method or does EMC equivalent model has same features and will get 600GB*12 or additional disk shelf will get lesser price than the product. Please help.