Question What PSU should I get? slightly confused

[A380-Fan]

I have all parts for my PC except for a psu. I am not sure why the prices for PSU's are so different. I think the thermaltlake GX2 660w is fine but I'm also confused as to why my estimated wattage is only 300 watts. Is this normal? My budget is around 60~70 dollars and am not planning on upgrading any parts anytime soon.

Here is the PPP link: pcpartpicker.com/user/A380-Fan/saved/XZ3fdC

Thanks!

 

[MrN1ce9uy]

Power supplies are typically most efficient at around 50% utilization; therefore, your target wattage should be around twice your actual consumption.

At the current market prices, I'd say that unit is decent enough for the parts you have selected.

 

[A380-Fan]

Ok, thank you for your help!