When I was trying to save for Miss Fortune (3150) I was grinding like crazy. When I got to my last 76 or so IP I played a game and came out being at 3149. I will never forget that.
i think it is even worse with lp, and you end up playing a ranked game for 1 lp that you could easily end up losing.
its a sign that you shouldn't buy that champion, something is going to go wrong. you wont climb