The following is my opinion.
The economy is PR has driven many people to loose their homes or move to the states, this means that there are good properties for less than in 2006 at the hight of the economy.
While you can find a good deal, neither the banks nor the people are giving their property away.Investments firms are buying cheap promising properties from the banks and putting them up for sale. In order to compete with them you need to go to the Auctions and bid on properties (which I plan to do in a few years for rental units).
You are not likely to find super cheap properties like 20K or anything less than 50K unless the roof has fallen thru and the windows are holes in the walls that allow rain to get it and trees are starting to grow inside the house. Most properties in PR sell for 150K to 400K, you can get something in the 70-100k in an "Urbanizacion" where houses are almost touching each others and you can hear the conversation on the house next door. You can find a plot of land in the middle of nowhere up in the mountains fairly cheap but you will be far from Supermarkets, Pharmacy, doctors and not likely close to the sea or most things a mainlander would be interested in. You can always get lucky and find a little property with water front but those are very hard to find and getting there may be a problem unless you travel by boat. I said water front, not BEACH.
The board imposed on Puerto Rico, PROMESA, could help the island recover or may make matters worse in the short term by squeezing money out of the economy, raising unemployment and selling the best properties to foreign investors in order to pay the bond holders. It is hard to say which way it will go since they have not yet even started planning what they will do. Likely they will do next to nothing until Feb next year and that will be just their first step, so do not expect things to get better in the next 2 years.
Likely you will not see any benefits until at least 5 years from now.
So ....... It is very important you understand that if you buy a property, it is not likely to go up in value by much for at least 5 years and if you try to sell it, you will be among the tens of thousands Puerto Ricans with a property in the market that will take at least a year to sell.
Pick something that you can afford, it is in a good area and that you do not plan to sell for a long time, if you are not sure, then rent until you find what you want. It makes no sense to buy a property with the idea of making money the short term, you may end up selling cheaper than you bough.
SO get something nice and over the next 3-5 years make improvements to the land and house/condo that others will appreciate but make sure you still make yourself happy with the changes, you will be living there and there is no need to be miserable making marketable improvements that will not pay of for many years.
I will be building in my property and have no plans of ever selling the place, what I will build will be for my family and my enjoyment. So to me makes no difference if the house prices go up or down as I am returning back for good to PR and will be buried in the family plot.
Some of you may disagree with what I stated above, but like I said it is my opinion and I am trying to open your eyes and help you get something you will be comfortable in for a fair price. Not trying to sell you the equivalent of the SF Bridge for a song.
Which you all luck.