We also broke even.
I take care of my parents financial details, including their taxes. They had H&R Block do their returns but in 2010, they forgot to electronically file their MD and US returns. They owed Maryland and submitted their check. When they didn't get their Federal return, I started checking and discovered H&R Block screwed up. They did file and refunded the charge for my parents return, and a few months later their refund check was delivered.
Flash forward to 2015, Maryland sends a letter to my folks say they never submitted their 2010 Maryland return. Oh-Oh... Yep, even though my parents send MD a check - and it was cashed, the return was never officially completed. And, Maryland says H&R Block screwed up and they owed an additional $125. So, we wait and wait for the notice. Five phone calls to MD later, they finally send the bill and my parents pay.
Since 2015, I moved their taxes to a well known local tax preparer/Accountant. My wife does book work and we decided she can now do their taxes, saving them the $250 annually. She rechecks their Maryland 2010 return, corrected by the State of MD and finds their correction was IN ERROR. She works for the state and calls the director. The director says she doesn't think they made a mistake, but will check and call back. Yep, THEY screwed up, my parents didn't owe anything, so now they are sending back the check....
THEN, my wife starts checking the returns prepared by the Accountant and finds he made two big errors in the past three years - my parents are owned another $2k on Federal returns and refiles all of those years.
So, if you get someone to do your returns, check it carefully!