Hi,
Odessa is a second biggest property spot in Ukraine after Kiev and thus prices will reflect this. I have a mate who invested in off-plan in Kiev back to 2002 and the developer was 2 years late with completion, not only that but developer increased the price whilst building paying no attention to PPC, bare in mind that this mate of mine is a Ukrainean and he could speak language etc... I would strongly recommend not to go for off-plan, if you do want to buy - buy complete properties. Personally I think there much better investments around that splashing out 1K per sqm (off-plan) and 1.5-2K per sqm complete.
Make sure you know someone who you can trust locally there. And bare in mind that courts do ignore facts in the hearings! if you ever come to that point.
Hope that helps.
if you want I can put in in touch with my Ukrainean friend and you can email him with some questions