I found my 'dream' jeans in River Island about 7 years ago. Dark stretch bootcuts with a thin line down the front and very small bits of distressing near the pockets.
I bought two pairs, wore them into the ground, went into mourning, then went on ebay and found loads of them on there! it was a 'hallelujah' moment.
I won't wear anything else in winter. They were £45 new but you can't get them any more. Roughly £18 on ebay and worth every penny. I wonder if people will laugh when I'm still wearing them in the care home when I'm an old laydee.
I think to be fair, one reason why cheap jeans are crap compared to expensive jeans is that the cheap jeans were bought on impulse, with the price one of the purchasing factors. The expensive ones will be a considered purchase, tried on, thought about in depth etc and so naturally will be a better fit etc as more thought went into buying them in the first place.
The reason that so many of my cheap clothes end up in the charity bag isn't that they are particularly bad in themselves, it's that I bought for the wrong reasons.