Hi - Check with your bank - I opened a free business checking account with Washington Mutual (now Chase), and it actually costs me less than my personal checking account with another bank. You may still be able to open a free business checking account with Chase.
If it is not that profitable a business it is not worth opening an account for it. As you rightly pointed out it does cost monthly to service a business account. The best thing to do is to keep a ledger that way you can log in money that comes in and goes out on the business. That will let you know where your business funds are. I suggest you open a separate personal account and keep that money separate from your own personal expenditure. You were thinking in the right direction. I hope second opinion has helped. Have a nice day.