Is it possible that the other buyer just so happened to have put in their offer the day before the price drop and HUD accepted it without ever advertising the price drop?  

I started a handwritten letter campaign and I have my first lead that I am very interested in. 

That's why many have a license, they may represent their own interests, when they do, they must advertise as being an "owner/agent or owner/broker" and disclose their position upon the first opportunity, generally.

The 25% vacancy seems a bit optimistic, though with an aggressive marketing campaign you might be able to do it.

Advertise on the Marketplace. 

Dodd Frank aimed squarely at mobile home financiers to occupants.Just advertise it in craigslist:  mobile home in park.  

With a direct mail campaign you can acquire some undervalued properties do some light rehabbing and put them on the market just below current market prices for a quick sale.

The first call I got on my first ever yellow letter campaign was from a guy who didn't have anything better to do with his life.

Vacation rental by owner, expect to pay about $1200 per year for advertising and fees.Please let me know if you have any other questions.

So, I recently sent my first yellow letters campaign to absentee owners and I'm only getting calls from investor and landlords who are not motivated to sell but the want to play the game only to see how much I offer and then say they're investors and they won't sale for that price, bla bla bla.