Never gone anywhere below 250 per byte since the year started. Last year I think the lowest I went was maybe 180/byte.
When I need a quick confirmation, I aim for bitcoinfees21's cheapest and fastest, at whichever has the lowest unconfirmed tx's.
When a tx is not urgent, then it's usually at the 250-300/byte range (the lowest of the yellow bars.never the orange ones. ^^)
When I make a mistake calculating my tx size and it ends up on the 10-20 blocks range, then I use the accelerator. It usually works.
Why pay the high fees even if I could wait days? Because I don't like my transactions(money/btc) stuck. They could be in wallets, storage, or even in cash, but never stuck in between.
And yeah, sometimes I feel it's a waste, but still.