Upgrade PSU and GPU?

My computer recently started crashing, and occasionally fails to turn after shutting down. I decided to replace the faulty parts, Graphics card and Power Supply, so that it would work normally again.
It is overdue for an upgrade anyway, so i don't want to try to repair it.
I need suggestions for a graphics card that can do some light to medium gaming, namely 1280x1024 and medium settings. For the power supply, at least 350w minimum, 450w preferred.
I have a budget of $100, which includes shipping.
Thank you in advance.