Investors & landlords

I think that is a very practical example of how to interpret this new rule.  Thank You!  I have a similar question.  In previous years, if you purchased a $900 window A/C unit, you would claim that as an expense, right? So, given the limit of $2500 with the new rule, how does this benefit, since I would still end up claiming it as an expense anyway? I'm not familiar if there is a cost factor when deciding if something as an asset to be depreciated, so perhaps I'm wrong in thinking it would be included as an expense to begin with.?