Nice house with great tenant - Should I sell it?

[Bruce Clark]

I currently own a house that I previously lived in for 5 years. I moved out two years ago, and it has been a rental ever since. The house is in very good shape (I used to live there) and rarely needs maintenance or repairs (fingers crossed). Also, I have a great tenant, who just signed her second lease. She pays rent early every month, maintains the landscaping - she really is perfect. The house currently cashflows $350 per month after all expenses are paid. (Rent is $650 and mortgage, taxes, insurance are around $250)

With all of this said, I am wondering if I should sell this house. I originally bought the house for $24,500 in 2010. I fixed it up before I moved into it and lived in it for 5 years. Right now I could sell it for $50,000 pretty easy and I only owe about $18,000. I am not an accountant, but it is my understanding that if I sold it today I could I would stand to make a $25,000 profit and avoid taxes on that money given that I used the house as my primary residence up until 2 years ago. Also, I could use the approximately $25,000 as a down payment on something larger - maybe a 4 or 5 plex giving me, at the very least, the same cashflow but probably more.

On the other hand, I keep thinking that I have a nice unit with a great tenant, that cashflows $350 a month. Maybe I should just keep it and not mess with a good  thing.

What do you think? Thanks in advance for your help!