I think 650w is enough, but I heard it is better to get 750 watt for future proof, as Gfx card will get more hungry in future
Seasonic S12III $99 or Focus GX-650 $175.
BTW are you just asking? Cuz I remember in the past you also ask before.
If you are looking for cheap PSU, you can consider Super Flower PSU.
Unless you are buying, I may have a Focus GX-650 still have warranty for sale.