Starting problem

I have a 1998 Durango with the 5.2 litre engine and automatic trans. When I turn the key, it will either start almost instantly, or nothing. Not even a click, and the starter does nothing. I removed the coil wire so I could crank the engine for a while to see if the battery was dying and how long it would crank. The engine cranked for a few seconds and then stopped instantly, it never slowed, but just stopped. I then turned the key again and it cranked pretty fast for a few seconds again, and then stopped instantly again. My guess is the battery is fine, but the starter is dying. Suggestions, please. Thanks, Mike

diegolocks10-----I know I can easily take the Durango to the repair shop, but I was hoping for some info. so I could replace the starter myself, if the experts at this site believe that to be the problem. Thanks, Mike

I just replaced the starter, for $115.00 and all is fine. If I would have taken it to a dealer, I would probably have a $500.00 bill. Thanks for all the suggestions.