The least expensive 550W worth buying is typically the recent Corsair CX 550.
I'm very glad you check for your PSU, that's a frighteningly poor one. Passive PFC and +12V rails that classify that as barely a 300W PSU indicates a supply that was designed for PCs of 20 years ago. I'd bet a good sum of money that the capacitors in there are bottom-of-the-barrel as well, as almost invariably is the case with these kind of dodgy off-brand PSUs.
I consider the odds that this PSU contributed to the death of your previous GPU to be quite good. PSUs like these are notorious for poor voltage regulation, inadequate filtering, and the cheapest 85-degree Chinese capacitors they can source.