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iMac Intel 27" Customer supplied the 1TB SSD. I have costs for related parts. TIA – Rio

Your first mistake was accepting the job. Never let a customer dictate what parts you are going to use. They are on the cheap, you have no idea of the history of this part. You have to clearly state that if you put the drive in YOU are not responsible if it works or not and your fee is the same. That being said, is this a replacement drive or an addition? Is the drive compatible? Do you have to do the formatting, system installation, data recovery, user setup? In addition you are going to need the cable and replacement adhesive strips the opening tool, see this guide: iMac Intel 27" Retina 5K Display Hard Drive ReplacementiMac Intel 27" 5K (Late 2014-Mid 2015) Hard Drive Cable[linked product missing or disabled: IF174-005-1]