I know some of you feel the risk involved and some feel that MC is too caught up in stealing the Pokemon eggs.
Know that the MC is poor, a good green grade Pokemon costs more than 10 million. That's just a Pokemon that has one evolution. If he wants a great one like Elekid, he needs 50 million.
The tournament is in 5 months so he needs a high talented pokemon. The tournament is a 2v2 and has great rewards.
Remember he can only contract a total of 6 Pokemon so every Pokemon he chooses must be great to achieve his goals. Currently, the only way for him to get a high grade Pokemon with no cost of money is stealing.
I am not sure if you guys understand my logic but my thought process will be the same as MC if I were in his place.
Also, him trying to make money through teaching Ice punch and flame charge is risky because MC is not an official taught tutor. He can't explain the reason on how he knows the teaching method or he might be the target of someone and get hired into a family as he is talented. Remember he is a civilian. Even if he starts teaching, it will take more than 3 months to completely teach a Pokemon as even he is not sure about the complete process.
So the only option is to take risks for a great Pokemon. I hope it makes sense. If you have any doubts, u can comment down.
There is an alternative option to take help from Ethan but remember Arthur has known Ethan for only a month as Ethan never explained the childhood story. So in Arthur's mind, they are just normal friends.