Not really, NO
Fully encrypting a hard drive completely replaces the contents in the drive with an image. Combined with a pre-boot authentication, a thief will find it hard to break into an encrypted image. Therefore, the greatest benefit is to enhance data security and not make part of an ROI report. An ROI report in information security context is sometimes used to justify any security expense from which an organization might benefit. It is sometimes related to an encryption of a hard drive but has nothing to do with it being a benefit.