I got mine from Pound Stretchers about 3 years ago - large case, not too heavy and very cheap (only about £20 or so) and haven't had any problems with it.
Its not a suitcase but weighs next to nothing, we use one all the time and even though its been crammed with all kinds of stuff, its never been over the weight limit
We use Samsonite they are expensive and quite heavy we got ours from a shopping outlet but they have been all over the world n still going strong have to say with lower luggage allowance we may be taking 1 hard case and 3 wheeled hold alls