There are cheaper power supplies with no MOV, Y-CAPs, CM / DM Chokes, while there are footprints in the PCB for these components. There are jumpers for CM/DM chokes!The main problem with cheap supplies is that they will never meet their specifications, especially not over time. As Evil Lurker indicated, Fuhjyuu caps are some of the worst (next to Capxon, Chhsi and Sacon.) In fact, 80-90% of all power supplies I repair have bad caps.
There is a case of a certain series of Bestec power supplies incinerating themselves and the motherboard when they go bad. A small 47u cap goes bad, which causes the 5V standby (+5VSB) to rocket to 12V, quickly destroying many components on the motherboard.