They either did a terrible job acquiring their list (absentee owners are getting multiple direct mail pieces a day from investors) or they tried being a copywriter and wrote a terrible message. 

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That usually means a cheap Chinese product imported by someone who doesn't have enough money to hire a copywriter or exported directly by a Chinese company without any English-speaking employees.

I’m considering hiring a professional copy-writer too and would love to hear if anyone else has.

But from a copywriting perspective that issue deserves some attention on the site, imo.

Advertising copywriting legend Gary Halbert used to say that if he were to open a restaurant, he'd want a list of starving people (with money). 

My day to day "job" is website development and copywriting.  

However, I would suggest that you look for a different target market than the affluent and, as you mentioned, study Dan and others' copywriting material.

The followup system when a seller callsIf you're not a great sales copywriter and don't know the proper strategy on how to make a direct mail piece work in your market, it's likely not going be profitable. 

What's your biggest hurdle when writing real estate ads?