I dont think so it can be repaired without cutting the skirt...because the skirt is not hollow from the inside and its not that the denter might just need to hammer it from the inside to take out the dent.
My car's skirt had a similar dent once and I got it repaired...and the denter had to cut my skirt, then melt the metal a little bit to bring it back into shape, then weld it back and paint it.
All this had no effect on my car's resale value...as its already been sold...it was just damage to the skirt (like on your car) and not to the body.