In order to win praise, unless you put in great effort like that, ?????
The only way I can translate the end of the sentence is "not having hardship is difficult" i.e "Unless you put in great effort it is difficult to win praise without hardship". But this is a tautology. Great effort = hardship. Have I got this completely wrong?
Edit: Thanks to Flaw's comment I now have that なきゃなんない is a contraction of なければならない so I get "In order to win praise, the fact that one should put in great effort like that is difficult. That still makes no sense to me. I guess it's my translation of 大変 that's tripping me up somehow?