450W PSU. Excellent power unit for a basic build. This power unit is super efficient usually delivering more than 85% power efficiency.

https://hardwaresecrets.com/corsair-vx450w-power-supply-review/

Prefer to trade in Tung Chung as price is a giveaway.

specs:

ATX12V 2.2
Nominal labeled power: 450 W.
Measured maximum power: 571.9 W at 47.8° C.
Labeled efficiency: Between 80% and 85%.
Measured efficiency: Between 84.3% and 88.1% at 115 V.
Active PFC: Yes.
Motherboard Power Connectors: One 24-pin connector and one EPS12V connector that can be split into two ATX12V connectors.
Video Card Power Connectors: One 6-pin connector.
Peripheral Power Connectors: Six, two cables with three standard peripheral power connectors and one floppy disk drive power connector each.
SATA Power Connectors: Six, two cables with three SATA power connectors each.
Real manufacturer: Seasonic