When is selecting "Other" acceptable in a historical analysis?

Problem: The Historical methodology has the option to choose OTHER if unsupported by a prior competition or cost analysis.  When is using "Other" acceptable in a historical analysis? 

As stated in other articles published here Why can't I use historical pricing as my analysis methodology when I bought the same thing before? or I recently bought an item, and I am buying the same item now. Can I use historical pricing as my methodology? the basis for the prior price must be valid.  If there is a large gap in time between the prior and current purchases OR if the prior price is uncertain, you likely do not have a valid basis for comparison.

If Other is not an available option for you, your company's Policies & Procedures do not allow for this option. Please choose another pricing methodology or contact the HelpDesk at [e-mail].