In the past couple days, I have been doing PS runs to the gold cap. And in the crews I've been in, it takes just over an hour to hit the 50k cap~
Each wave of saws, on normal and at CL 5.0, gives on average around 600 gold per wave (sometimes more or less; this is just general observation). I have the highest ghi luck boost, integrity, fitness, rr4 coyote, and rr4 divinity on. This gives 31 luck, or 31% more gold from killing monsters. There's roughly 7 waves of saws total in each round (maybe 6). 4-5 of them to start off PS, then the Mama saws spawn... and in another 2 waves of saws, Papa Saw usually appears~
So assuming the 600 gold per wave, that's 4200 gold on average from drops by killing the mobs of saws. When you include the bonus the extra bit from killing Mamas and Papa, + the final reward for completing the saw mill, it brings it up to around 4500 (again, roughly)~
Each wave takes, for the groups I've been in, about 40-45 seconds from the time the first group of saws appear to the next group (we just stand in a corner and all use fire rain once. If there are any surviving saws, they tend to be picked off with 1 round of water balloon). So if we factor that in (and using the higher value), it's about 5 and a quarter minutes. Factoring in killing papa saw himself, then leaving and restarting the instance, it comes to about 6 minutes when being efficient~
With that said, I just don't really believe you~
I also do not believe the accusations of making more than that per run. Unless you deliberately do not finish off the Mama saws and/or Papa saw as quickly as possible or somehow get them stuck~
...Sorry for the rather long "counter" to your statements. But yeah, those are my observations based on what I recently observed and know about the game~