This will tell other folks in this board the various markets they may know that could suit you better than just Las Vegas.Another thing I'd like to know are you local to Las Vegas and is that why you have chosen that region first to attempt investing in real estate?  

Your play here is gambling on appreciation hoping you make your money that way which is just that gambling. 

As it turns out they declined my offer and have chosen to sell the houses individually regardless how how financing was structured.

Or, the seller just might have chosen another offer for some other reason.  

I got all my families' money out of that speculation and gambling game.  

Sell to my long-term tenant for $400,000, and invest proceeds in stock market, while avoiding new roof expense in a year or two and taking a gamble on new tenant when current one leaves if I don't sell him the house.2. 

Or is it a gamble and the original owner could come back and reclaim the home?

You may have to speak with a number of them before you settle on one, make sure to ask them tough questions about the area they are in as well as their knowledge of your chosen investment vehicle (MFH, flip, etc...) and see how they respond.  

@Raden Mantuano not only are you having to bank on appreciation, you are gambling on where interest rates are going to be in 9 years.

You have to plug your cash into a "best possible us" filter and weigh options based on your chosen path.$50k isn't much, so leverage is probably key...but that doesn't mean you can't allocate to multiple areas...for example, hire a marketing firm and build your campaign for off-market properties...and leverage bank money on a buy-and-hold.