Background first

I financed my first house 12 years ago. It is a 3 bedroom and 2 bathroom house and is a little over 1000 square feet. It has the biggest back yard in the whole development. Good neighborhood. It is across from the local high school. 2-5 minutes from everything in town. I paid about $57,000 for it if I remember correct. I am currently at a 7.59% interest rate. I know that's high, but I was 19 at the time. I currently owe about $45,000. I spent $15,000 last summer fixing up the inside (new tile throughout the house, new trim, new paint, new kitchen, etc). I put on a new metal roof about 2 months ago. Most of the houses in the neighborhood are being priced at $90-100,000. I know one recently sold in the $80's. So, people may not be getting $90-100,000.

My house payment/insurance/taxes are right at $600 per month. I am renting it out for $800 per month.

Now my real question.

Is my best bet to get another rental the beginning of next year to refinance this house (hopefully at a much lower interest rate) for $10-15,000 more than I owe (if possible) and use that money plus money I have in savings to put down on a new property?