Then find a new buyer for what you think it is worth. 

Hello, I'm new to buying/flipping and all the information I've read suggests that I should obtain a specialized buyer's agent. 

Yet another reason to hate the auction companies:  I had not yet paid the deposit b/c the auction company insisted on a clause in their contract that said that if the buyer defaulted on the contract, buyer would forfeit their entire deposit as liquidated damages. 

Where would be the best place to find buyers for commercial property in the $1-$2m range?

I am the buyer.

Marketable title is title that doesn't have material defects... and as such the buyer cannot claim there is a title problem and refuse to close. 

This Contract Is Not assignable by Buyer unless otherwise specified inAdditional Provisions.So in the additional provisions area you just state that the contract is assignable (with or without perimeters). https://drive.google.com/drive/folders/0B1VD36mBqe1EfnJaMGl3MVBxX0Zva3RVbEY2amVuc1Y4SFh2X3JDZTVHeGxUUVRzaGdDMVU

I have had one realtor bring me buyers for five different houses in the past.

In most states, including TX, the owner must disclose the inspection to future buyers, by law, so he/she loses and the future buyer gets the benefit of my hard earned money. 

He might be right, and since we are first time buyers, it makes sense.