The gas tank is a beeyotch. You have to drop the muffler from the cat back, the rear driveshaft has to come out, it at least has to be unbolted from the diff and moved out of the way, if you can. Some covers, the connector pipe that goes between the two sides. Getting mine out took me about 8 hours and I had a lift, and a lot of problems.
Going back in took me about an hour-hour and a half.
I would say you will have a hard time getting any kind of an estimate that comes close to the actual price. If everything goes right you are looking at at least 3 hours.
Now, before you do anything, get a freind, pull the back seat out and leave it in the garage. Pull the cover to the fuel pump, grab some rags and a screw driver and go for a ride.
Make plenty of hard left hand turns and make sure you don't merely have gas sloshing out at the fuel pump gasket. Mine isn't tight enough and every time I make a hard braking left hand turn I smell gas. I put a new one on but I have to get back in there because I'm not getting a good seal.
A 3 dollar O-ring an a half hour beats the hell out of dropping the tank for no reason. If you're really lucky you will have a leaky hose clamp and your freind can indentify which one it is