Which harmonica should I buy?

So I'm still a beginner at playing harmonica but I want a new one. Right now I'm using a plastic Hohnor one I got a long time ago. I'm looking at buying either the Hohnor Blues Band Seven Piece Harmonica Set 1501 (key of C G A Bb D E and F) Or just one nice harmonica. Which do you guys think and if you recomend one nice harmonica which key? And for around 20-30 bucks please. Please only people who know some stuff about harmonicas. I like to play blues.