First, If the chinese attorney help him do the illegal paperwork on the purpose, he/she would lose his/her licence and also he/she could not charge only $3000 for 140 and 485 both for illegal person who apply GC, he could definitely charge more than that. The immigration officer is not so stupid not to check applicant record.
Second, Nobody would like to pay $ 30,000 to get a job which kill chicken, if your story said he got $30,000 per year kill-chicken job, it would be more reasonable.
I have some more seasons to point out you make this story, but no time to write.
If you would like to learn how to make story, I could teach you.