Analyzing a Deal for Profitability

[Mormon Redd]

I am trying to get in to multi-family apartment investing (5+ units) and have been searching for a property that I could reposition. In a training program I did I was taught to estimate costs at 50% of gross income when analyzing the financials, but after looking through dozens of marketing packages I have only found 3 where reported expenses even approach 40% and most are around 30% or closer to 20% of the operating income. Is this 50% being too conservative? Those of you who have owned multi-family, what percent of operating income have your expenses been?