A quick rule of thumb when working out if a bike is likely to be legal or not... find out the NEW MSRP of the same bike in an overseas market (I use the USA market for this most of the time) then multiply that MSRP by two... then convert the currency (e.g. from US$ to CNY) and this will give you the MINIMUM price that the bike should be, in most circumstances. Often though the MSRP can be multiplied by three to really get an indication of the likely PRC MSRP at a dealer in mainland China. Based on this basic arithmetic those 3 bikes you mention are HIGHLY LIKELY to be anything but legal. Just sayin...
So if you think that Laoban's prices were like day light robbery, please sit down for the prices you will be entertaining on any legally imported bike above 250cc here.