I agree with Mehran. The property across the street that's on the market for $106k is 100% irrelevant. It could be on the market for $1 million, but that doesn't mean it's worth it. Very important to look at sold properties within a half mile and within 6 months of the subject property to determine value. The closer and more recent, the better.
As far as it only selling for $30k, it may not be a bad deal. If the same tenant has been in there for 10 years, then it definitely needs updating, combined with the seller's motivation, $30k might make sense. Just go in there with an inspection contingency to CYA, get an inspection and you'll be good. And plan on renovating the place after that tenant moves out.
Great cashflow, but financing will be a huge challenge. You might want to examine private money for this deal, and pay them back on a refi. You might even be able to get some cash out to invest in your next deal :)
Good luck!