Figuring out what's up with a "Too good to be true" deal?

[Tyler L.]

I'm currently looking at a 6 unit multifamily deal that seems too good to be true. Everything seems to be okay, but there's one glaring issue: every way I've analyzed it, it's been shockingly undervalued. Basing it off of comps, it's priced at about 60% of projected value. Going by square footage alone, it's at 50% of value. The cap rate is about 50% higher than the area, and if rents were raised to market rates, it'd be double the cap rate. It's not a foreclosure, and there have been no murders or meth labs that I have found online. The realtor has said the sellers are "hoping to move on to something different." 

Since this would be my first investment deal, I feel I'm missing something, and want to know what to be on the lookout for.

Here's the facts:

6 family home in a b/c class neighborhood, with a lower than average crime rate

100% occupied

Renovated 4 years ago 

Population is steady, jobs are mostly in health care and warehousing/distribution

Building is older (1890's in a neighborhood mostly built in 1940's)

County is about 100,000 people

Located right in the center of town

I recognize the property may be worth less because of its age, but certainly not 40-50% less, especially when it was renovated a few years ago. It's also not a foreclosure.

Of course, before I actually did a deal I'd have it inspected and do plenty of due diligence. Is there something, in particular, I should look out for? What's the most common reasons a deal like this is "too good to be true?" Of course, there is always the chance that the owners really do just need to sell quickly. And while I'd love for that to be true, I certainly am not betting on it.