Same boat, I used to dump my GPUs after a year or so but I always regretted it. I think its better to use them for 5 years at least , since they are paid off
I have yet to "dump" any GPU I have mined with, unless it flat out died.
If I can't mine profitably with them, there's other stuff I can do with them 'till some new coin shows up that IS profitable.
In dump i meant replace them with newer models, or sell them when profit declined , not sure why you think i meant dump literally lol
who would just trash a 300 gpu with a 3 year warranty /boggle