I'd say depends on the condition of the seat you have and the seat you can get. If your is really clean you might just want to have it repaired.
A windshield installer put a cut in my driver's seat, and had it repaired by a leather repair specialist, since my seat otherwise is in great shape. I know they are just putting vinyl goo filler in there, but they did a really nice job it looks great. So it is possible to repair it well.
The used seat cover will be a bit unknown if you buy remotely, will there be scratches you can't see in pictures, stains or dirt you can't get out. For whatever reason boneyards don't seem to treat parts like this very well, cars have windows open in the rain, the techs never wash their hands...I've bought some wood steering wheels and other parts and they were always a bit rougher than you would think by the pics, and sometimes that is a hairline crack which makes the wood part basically useless junk. These guys are not conscious of the value of a nice clean part like a leather seat. Just some experience to keep in mind. If you buy locally and see the part in person before you pay it is a different story.