For this home you describe, the advice Juice gave is the way to go.
If you sell in less than 12 months you pay taxes based on your income tax bracket, which is going to be much higher than the 15% capital gains tax.
Another issue: are you SURE that it will "only" be $10-15K to "fix it up"? I've under-estimated a few times and have gone over budget (I've flipped 3 times).
Another issue: as mentioned, depending where you live, the days of flipping are coming to a halt. Interest rates a higher (than the last few years), homes are way, way over-priced in most markets. In fact, in some markets (Vegas, NY, San Diego, Pheonix) it is predicted home prices will drop 2-5% or more!
Also, if they are asking $140 for this house....offer $125k and see if they bite. In today's market (a buyer's market) DO NOT offer what they are asking! Leave your number w/ the realtor and tell him/her that if the seller is serious about selling have them make a reasonable counter-offer.
But, at $140K - if you pay cash for the renovations and put down 5-10% your mortgage payment should be less than (or right at) $1000. If it's a 3br/2ba home you should be able to get that if the neighborhood is as you described......
I live in Jacksonville, FL and our market is predicted (by Forbes Magazine & MONEY magazine.....and several other real estate experts) to be the strongest in the state for the next year to two years. Real estate in Jax went up, just like everywhere else in the country, but not as much as Miami, Naples, Sarasota and some other spots in Florida. Forbes predicts about a 9% gain this year.