uhhh... yes, you read it wrong.
you should become a "legit" company when you figure out the laws and rights that pertain to you, as a business owner in your region. in the states there are several ways to become "self employed."
it doesn't matter how much you earn to claim income. you can claim as much as you want. when you own a business (in the states) there are things call itemized deductions you can claim to offset the annual income.
personally, i own property and equipment, so it is important to claim the amount it takes to maintain that equipment and property. this is deducted from my annual gross income.
if i made $80,000 last year in profit but spent ***$40,000 on equipment purchases and maintenance etc, then i can deduct that figure from my annual income and it would appear that i only made $40,000 (because 80k minus 40k = 40k). tax write-offs can help you gain top line revenue at the end of the year/quarter. the reason (some) engineers get screwed over on taxes is because they don't realize that they are responsible for tax deductions/don't pay taxes, then end up with a bill from the IRS.
i don't know where you live (country/state) but taxes typically work the same (in most places) it just depends on what you are being taxed and the authority's purpose for taxing it at the end of the year.
typically, the more you profit... the more you will end up paying the government at the end of the quarter/year. however if you learn to regulate the deductions (with a great accountant) you can decrease the perceived income furthermore end up on top at the beginning of the next quarter/year.
i'd say... the most important thing you should do (before starting a "legit" studio) is make money that you can arrange to make deposits into a business account. then apply for a business license and finally higher an accountant. i think you should also learn the rules as they pertain to you if you want to bend them.
good luck, sonny-jim!