Houston Fix and Flip margins

[Joseph Maurer]

I'm new to real estate investing and I had a quick question for investors in Houston that are rehabbing and reselling. What profit margin is common? 

The reason I'm asking is because I found a motivated seller in Spring Branch who is looking to sell. The ARV is 220 - 230K and repair costs are 20 - 30K. The seller stated that he's received offers from 140-150K. Using the Flip calculator I found that a MAO of 140K would carry a flip profit of 20% at ARV of 230K.

Does 20% work? Also I know holding costs depend on different factors but even going as high as potential rent + expenses per month make the numbers seem tight. Am I missing something?

Thanks,

-Joe