Given your emphasis on mastering the foundational aspects of real estate, I’d love to hear your advice on how I can effectively integrate these principles, laws, and finance into my strategy.

With that said I do see plenty of referral fee agreements online but most are for % of listing agents commission rather than this colleague paying me 3% of the sale price.

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Try an online permit.  

I would use online platforms (zillow, etc..), rentometer, and calling competitive properties to "price shop".

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Texas allows online sales now, but not many places doing it.

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Getting a real estate license is not that expensive and it's all online now, so it's pretty easy to get. 

You can also check their reviews online at Google, Facebook, or Yelp.