What Ccino said️ Getting hired only helps you upgrade until you have 2500/2500 stats, or 5kcs as its called. Then just do jobs and participate in parties to make more money and upgrade more. As you upgrade you will be hired again so that your stats match your hire price
You do not need to do anything, there is nothing wrong about being overpriced. But if you do care... which you shouldn't, then do jobs,parties, farming and such sonyou can upgrade.
You will always be op if your pupils actually wants to keep you, or if a tut trader hires and sells you.