I have to agree. An "epic lvl3" weapon really isn't epic when it is only good for 1 level because as soon as you hit lvl 4 you find a "normal" weapon that out damages it. True the epic/unique weapon usually have some sort of resist or added bonus damage to them.
I honestly think if they just changed the names to be "magic " instead of unique/epic it would make more sense, and have those items be truly unique/epic.