I went to some lengths to get portable scales - on ebay eventually. The ones I got had a silly hook on the end shaped like a V so it slipped off the handle of my one suitcase with a conventional handle and didn't work at all for the other one which had no actual handle on the top. Even without that problem, there is the simple difficulty of how one holds up the bag to weigh it. When you get to 25-30kg (which is why you bought the scales in the first place) the bag is certainly too heavy to lift clear off the floor AND read a number. Save your money and space in your suitcase, I say.