Surely, if the locals in Croatia cannot access mortgages easily and if foreign banks are unwilling to give mortgages on Croatian property this will mean that the market will be limited by these factors. This could mean that the second-hand market may be virtually non-existent, unless you sell to another "investor" from Ireland, England or Germany.
Builders have built too many properties in many of these areas because of the demand from foreign investors but the locals in many of these E European countries cannot afford to buy these properties. The fundamentals in these markets are not very clear and it is not a certainty that you can make gains. Some Western investors may have been remortgaging properties in the West in order to buy E European properties and they will now be begininning to find it a bit more difficult with increasing interest rates and banks strengthening their lending criteria.
If the locals cannot afford to buy these properties and the only people who can afford them are other Western "investors" then this indicates that prices are out of touch with the economic realities of the countries involved. That coupled with an oversupply indicates that the only way to sell many of these will have to be to reduce the price.