Today only. Newegg has the Antec NEO ECO 620C 620W Continuous Power ATX12V v2.3 / EPS12V 80 PLUS Certified Active PFC Power Supply for $50 - $20 rebate [Exp 12/17] = $30 with free shipping.
^ But is it a Neo Eco? Different models can't be expected to have same fan or thermal RPM ramping. Then again if you still have the PSU there are ways to slow the fan down, for example soldering a series ~68 ohm/1W+ resistor onto the positive power lead.
I have an Antec 500W PS that is so loud that it couldn't be used at all.
^ But is it a Neo Eco? Different models can't be expected to have same fan or thermal RPM ramping. Then again if you still have the PSU there are ways to slow the fan down, for example soldering a series ~68 ohm/1W+ resistor onto the positive power lead.
Open it up and replace the fan.