I recently bought an EVGA 3080ti FTW3 for $820 and, if the performance is a huge uplift and price isn't ridiculous, will use their StepUp program for a 4090.
I do hope the 4000 series undervolts as well as the 3000 series.
I can get slightly better performance at lower fan speeds, temperatures, and voltage vs stock on this card. In the handful of benchmarks I typically use, stock the FTW3 boost range is 1850MHz to 1895HMz with voltages 0.98Xv to 1.081v. When undervolting it to 0.925v, it will do either 1905MHz (intensive RTX) or 1920MHz (rasterization). I can't even hear the card in my case over the projector fan and the max temp is low 70s C. This card becomes parabolically more picky with increased clocks, even as I add voltage. Not worth it. I could muster about 2.X% more out of it when adding +150MHz to the clock, but with ridiculous heat and fan speed. Just not worth it.