What would be a good fully/semi modular PSU under $70 for this pc?
The EVGA G2 550W is an excellent unit for that price. Strongly recommend that one.
That Windows key isn't legit for that cheap and that AIO is of pretty bad valve.
PCPartPicker part list / Price breakdown by merchant
seasonic m12ii 620w evo
but if u can eet EVGA GS 550 OR G2 550 for under 70$ will be better