Without knowing what your PSU it is hard to judge.
Safest thing to do is leave it off.
As others have urged, do not go cheap on a PSU, it is the most important part in your computer as a cheap PSU can fry the rest of your computer (so have even started house fires).
A quality PSU can actually output its stated watts (if not a little more), has safeguards in it (like over voltage protection, short circuit protection, etc) to protect your parts from damage, as well as having quality capacitors and other parts that make it built to last.
A cheap PSU wont be able to stably output 60% of its load, and lacks any protections to prevent the PSU from frying the rest of your computer.