I had always assumed that at a tenner a go you threw them away when they got too dirty
The cheek of some people!
Nothing of mine gets binned for being grubby, they are usually in that state when I acquire them. Whilst it's true that my most-ridden bike, the Raleigh Pioneer Trail, did only cost me a crisp tenner to buy (but another £40 to get it sorted), I have on one occasion pushed out the boat as far as £43 on a used purchase.
I didn't even need a lie down to recover afterwards, as I felt that for a full 531ST frame in my ideal size, it was not overly extravagant.