Relax - by the time you get there, you'll have it figured out. $30.000 is nothing. Only if it's $30K a day, would you have to be creative.
The IRS will only come after you if they think you cheat on them - and that's the key to your question. Other aspects that are illegal may also attract attention, but $1000 in cash a week is no problem - and if it makes you nervous, just say you're self employed - and pay taxes for the money.
It's not a real problem - the money-part isn't. Now - selling controlled substances on the other hand is - unless it of course is all legal, medical etc - and you're paying your taxes. The IRS doesn't have monitoring of your accounts like that!
You're mixing apples and oranges. If your accounts become subpoenaed - it's because you're accused of acquiring money through illegal activity - like selling drugs.
File your taxes - show a realistic income, and pay your taxes for that amount - there will be no questions.