As far as salary is concerned, by the time YPIP 4th Batch is ready for postings, their salaries will have increased to 50K+ per month (exclusive of all allowances). Not to mention other benefits granted by SBP/BSC.

But anyways, regardless of salary, you should appear in the interview. What's harm in there? In case you're selected, you will then have two options as to which direction you want to take your career to.