1. delay or impede the progress of someone or something
don't let that set you back
To 'set someone back' is a phrasal verb meaning to delay the progress of someone or something. If you set someone back you may, in fact, cause them to regress in some way or cause them to run late or behind schedule.
2. cost someone a particular amount of money
how much did that set you back?
You can say 'how much did that set you back?' when you are talking about money or how much something cost.