I have 2 successful businesses without a degree, but getting one help me?

[Brett Deas]

For a little bit of background, I am currently an agent and make 80-K100K a year, and I also syndicate unique stay vacation rentals. I currently have about 3M in my syndication company, on track for 5M end of the year, and was able to build this all up within the last 2 years. 

I still have gaps in my knowledge and have thought about taking courses to try and fill the gaps. Not really for a degree but to help me run my business more effectively. I am thinking about either accounting, normal administration or construction management.

What do you all think? Should I take some courses or keep going on the path I am on. And if you do think I should go any recommendations on good online universities?