No, your logic doesn't. You don't need to spend over $100 just to get a decent PSU, period.
Yes, it does need explanation. LC isn't on the list, and the OEM of this unit isn't on the list. So, please, explain what the point of posting it here was.
Requires 50A?!? LOL... It is about Watts, because you can derive Amps from Watts. The card uses 180w, thats 15A. Yes, the OP's PSU can provide that. A single rail of the OP's PSU can provide that.
This is an exception.
The OEM has already been mentioned in the thread.