Just looking at my own state (Michigan) I can form the most "complicated" entity for $60 filing fee. Using a fill-in-the-blank form online. And have it approved the same day for an additional $50. Get an EIN online from the IRS in 10 minutes. Walk to a bank and open an account in about another hour. Annual renewal fee is $20.
In less than a day and for $110, I have a corporation, EIN (federal tax registration number), and bank account. Open for business. An LLC is the same, just a different form filed with the state.
I can then open credit card accounts online in the business name, register for sales tax online (get the license in about a week), and open a stripe account.
Oh, and a businessowners general liability insurance policy is costing me $205 per year. $1 million in liability coverage.