Well there's also another factor that you have to consider...customs and tax charges. If i order from outside the EU my beloved government will make me pay at least 19% VAT ( and they include the shipping charges... ). So items that are cheaper in Japan, Singapore or Australia may be more expensive than something ordered inside the EU once they get to my doorstep.
For example a Hiro kit is cheaper if i order it from Hiroboy than HLJ because of that.
Generally i always compare prices in different shops and then order based on the total including shipping and tax. At least you can do that nowadays very easily from your desk. Great improvement over "ye olde days" :-)