Based on the little known, it sounds like a great rental that you should keep. You don't hear of many properties that meet the 1% rule, not that it's a great gauge for rentals. I assume your mortgage is nonexistent or very low. Annual rental income might be considered 23k, minus 3k perhaps of expenses, so 20k in your pocket. Is the place in good shape or getting run down? Will it need new hvac or roof, etc? Do you find yourself working on it more than you like?
If you sold, depreciation recapture might be 20k, capital gains 140k, 15k transaction fees, so if you paid 15% (depending on what your income shows when you're doing taxes) on that, you might pocket 120k or so? You'd need stock market returns better than 15% to match what you're getting as a rental.
My math is pretty sloppy, so I'm sure you have better numbers you can more accurately calculate this with. Can you give us more information?