JackT,
You get what you pay for. Earl Sheibs will paint your truck any color for about $129. Macco will paint it for about $300-$400, buth assume that you do not need any body work done. I'm pretty sure you will not like the results you get from those places, especially after a few years and the paint starts to fail. If you plan on getting rid of your Sport Trac right away and you have bad paint, these cheaper places may be a cheap alternative.
A good quality paint job will cost around $2000-$3000 using the same paint formulas as the Ford factory uses.
If you get into special pearls, candies, and color shifting paints you can start at about $5000-$8000 and can easily exceed $20K. Some of those paints run over $1000 per gallon just for the paint!
...Rich