For me I would never attempt to do my taxes by myself unless it was basic. When it is a business there are more things that need to be considered and the rules are constantly changing.

Years ago I sold party lite on the side. My FIL always did our taxes (the farm books and my basic tax return). He was a school principal for 30 years. That year after he did our taxes I decided to take them to an accountant just in case. I ended up getting an extra $200 back through the accountant. Eventually my husband agreed as much as it was great to save money every year, by going to an accountant with up to date knowledge of everything that was claimable made a difference. We managed to pay next to no tax when we quit farming. Our FIL now uses our accountant too.