Hello! I have a classmate who is upgrading his PC with my help. He will get a new case, a Ryzen 5 2600, a MSI B450 Tomahawk, a Seasonic S12II 620 W, 8 GB of 3 GHz RAM and he will keep his GTX 1060 6 GB and his SSDs and HDDs. Because of this, he's looking for to sell his older parts for cheap: a 20$ case, i7-4790, 300 W PSU, cheap motherboard and 8 GB of DDR3 RAM. The problem is he had an old OEM AMD R9 255 for me, wich isn't good enough these days, and I will be putting an RX 470/570/480/580 (whatever good deal I can get) and a SSD, but I don't know if a PSU with 300 W will be capable of this. Could you help me? Thanks!