Why do people play the lottery or gamble in Vegas? 

Market timing is akin to gambling IMO.Make good fundamental choices and over the long term you will turn out to be right more than you are wrong.

I know I could theoretically force appreciation through basic value-add improvements, but I'm just scared that theirs a ceiling on those neighborhoods and if I take the gamble with 15k in rehab, that it will never appraise at 100k.

I'm a hard-core brand guy (10+ years as a branding consultant), and what I can tell you is that authenticity is the key--in my opinion--to doing this well.  

I try not to gamble with my investment money or my clients investments and can usually identify a good deal in a very short period of time.

It's a 50 cent gamble so it's worth trying.

At least the last half decade has proven this to play out.. compared to cash flow were hey we are going to do this and gambling that rents go up and that cap rates stay low and credit will be where it is today and then in 5 to 7 years if everything aligns we exit.the pros on those of course is tax treatment and income as you hold and pretty much every syndicator out there will take a 100k investment. 

You lower your own equity investment and thus you:- Increase your IRR- Lower your own personal risk if the project goes southIt's easy to make money when you're gambling with other people's money.

That option has always seemed kind of scary to me, and too much of a gamble.

Charles, I also gamble when investing in stocks.