Do you really have your heart set on Croatia?
The joke we make on our site is:
Q. What's the similarity between cheap property in Croatia and sunbeds?
A. The Germans grabbed them all early.
Dubrovnik is looking very expensive already. There are some more affordable coastal property around (after all, Croatia has plenty of coastline to choose from),but you need to be very selective if you are looking for good growth potential.
Have you considered neighbouring Montenegro at all? The geography and climate is very similar to Croatia, but the market is not as established as in Croatia.
The Russians are snapping up property in huge numbers and some resort areas are already expensive, but there are still areas that are up-and-coming where you can expect to see really good growth over the next few years.
If you Google 'propertastic', you can see some figures about how the two markets compare side by side.