Of course, you can buy eyepieces and barlows that would cost a lot more.
In my opinion, they are quality components. They are serving me well. Of course, you can buy eyepieces and barlows that would cost a lot more. But the gains you as a beginner would see are in no relation to the difference in cost. The gains are subtle and take some experience to fully appreciate. I would strongly advise you to not "upgrade" anything on the scope itself at this time.