at the stratos feric prices, american real estate is a bargain. >> the police per square foot in new york city is $1300. that's a good bargain considering the fact that sydney, london are at 2100 a square foot and above. >> reporter: this economist said chinese nationalists are here to stay. >> this is not a quick investment scene. many of the chinese buyers, they want to put some money down into a property and rent it out over time, if they are not using the property themselves. >>> realtors catering to buyers say most don't use mortgages. 99.9% all cash. >> all cash. >> effectively shutting out american buyers. >> if you have an international buyer, and says i can close in two weeks, it puts someone who needs financing at a disadvantage. economists say they are helping because mortgages are funded by international investors. >> the chinese is one of the major investors that puts money into mortgage-backed securities, but keeping interest rates low for the average americans. >> reporter: most average americans are not looking for places like these. those that are. no matter how low