Potato... case + PSU + keyboard + mouse + speakers for $45 is scary. All are going to be crappy at that price.
You can skim some cash off from the ram. You can get corsair valueram or something like it for $80.
I know you're already looking, but I think the major thing is to get a better PSU/case.
Look at Antec for combos otherwise get a name brand PSU and whatever case you want.
Seasonic, OCZ, Fortron, Sparkle, Antec, Enermax, etc. for PSU.
For $30-ish speakers, I think
x-230s would be a better option.