There are also several articles that discuss how to estimate rehab costs.

Use the Biggerpockets calculators to help you with estimating the costs and they also will print out to help you get a loan.Always do a cost evaluation before you make an offer and see it too.. 

Do you have an estimate of the costs to renovate the interior?

Chances are good that his credit says, "Foreclosure proceedings have started".

I'll give them a call for an estimate so I can figure out if I want/need to finance it. 

I would strongly recommend that you instead of starting with a foundation company, have a structural engineer come out and take a look at the property to get a feel for exactly what foundation repairs are needed.You can then have foundation companies bid on the engineer's report to resolve the issues to avoid a situation where you are allowing the foundation company to come up with the estimate themselves as I have heard that foundation companies estimates tend to come in all over the place without an engineer's report to work off and limit their repairs.I will PM you the guy that I used for a property I was looking at recently.   

Did you include Holding costs in with the Rehab estimate?  

The economy is to blame but local politics have played a role in the demise of Arecibo as well.I'm not sure how long your most recent visit was or when you are planning your next trip, but I do hope you get a chance to view some of the other " non tourist" areas as you may be pleasantly surprised at the resurgence (albeit gradual) of some of the surrounding towns.I've been a resident here now for the past 4 years and I currently work as  a lender at a local mortgage bank and also am now getting more involved with RE investing here.

There may be a chance for relocation assistance (usually $3,000) for your seller at closing depending on who their lender is. 

I see a property where the numbers look like they might be good that is in Flood Zone "A", 1% annual chance of flooding.