If you have limited budget but like to try different kind of lens on you digital camera, you probably have some experience in buying/selling lens on ebay, through photography equipment forum or at camera shops.
I'm not a frequent trader but did it regularly. Though we should not have any preference to people from different countries, the fact is that the price in the same conditions lens (eg) is generally higher in HK or PRC market than that of US or EU countries especially they are sold by individual not camera shops.
It is like a rule as per my so many years' buy and sell experience.
If you are going to buy or sell camera equipment, personally suggest you trade with the latter one(s).