Kp1,
Based on this and other threads started by you I cannot decide whether you are in the middle of the biggest panic attack ever or is there something going on that you have not been entirely up front about. Now I am not wishing to be rude but would you take a deep breath and stand back from your situation for a wee while,
Have you gone to Budapest to see what you have decided to buy or not? If not why not? If you rushed in and bought without knowing anything about the city or the development then you seem to be trying to repeat that mistake again by rushing out of your initial investment without any investigation either,
Go to Bp as previously advised check out the devlopment.talk to an independent estate agent there, a letting agent and an independent lawyer. Bring your documents with you, presumably you have a copy of your contract and you should have received an english language translation of it also. Get the lawyer to advise you of all consequences of pulling out.
When you have done all of this then make up your mind,Pulling out may well be best for you but you will be doing it with your eyes open. On the other side if you are not prepared to go to Bp at least once and make those enquiries then you probably should not be involving yourself in the overseas property market at all.
Whatever your reasons for backing out after having signed a contract not liking or losing faith in your estate agent seems to be a very strange reason.