Curval,
If you are seriously interested in buying property in the US you should hire someone who knows US tax laws.  To lose 50% of the value because of the estate tax would require remarkable financial ineptitude.  
First, there is a $1.5 million exemption.  How much property were you going to buy?  Secondly, if you leave your property to non-US citizens, I'm pretty sure they don't have to pay a US estate tax.
If you can afford to buy more than $1.5 million in US property, you can afford a decent tax attorney to guide you through the paperwork.
ra