If the blades are adjusted properly, then any nick that shows on the
finished piece must be in all the blades. One quick fix is to slide one
of the blades a little to one side so the nicks are not lined up.

I can't imagine buying a new planer is the best approach. I'd bet any
decent tool repair shop could swap the old for new blades for a lot
less than the price of a new planer if you can't get it done on your
own.

BW