What is the estimate, etc. to remove and replace a surpentine belt?

If you have the 3.8 or even the smaller engine it takes about .6 of an hour and a good belt goes for about $80, so figure around $135.

Buy your own belt for under $40 at a parts store, $30 for a Goodyear belt (4060922) at Amazon. Shops will double the price you would pay at the parts store. It is NOT impossible to replace the belt yourself with one tool to take the tension off the belt where the automatic tensioner provides constant tension. The tool is available at auto parts stores if you do not already have a 3/8 or 1/2-inch drive extension/long wrench and a 15mm socket for this year Le Sabre. One tool kit designed for various belt replacements is under $30 at Amazon, although some cost much more.