I mean masters is a huge risk. Let's say you get a 2.2 for undergrad at a non-prestigious uni and a distinction for masters at a reputable uni. It only balances out.

You don't also get commensurate pay offs. No firm is going to really care about your Masters unless you graduated top of your cohort at Ox or Cam.

The odds of you getting into one of those schools with poor undergraduate performance is already slim (let's say you get an okay school through a legacy programme or through some generous donation your parents made) what more doing well.

My advice is practical. Get experience. Don't throw money at the problem.