$2500 to change out just 1 tensioner? I would bring it to another shop because that is under $200 will parts and that's including all the seals if you have to pull the timing case off. I just replaced my whole timing assembly for alittle over $1000 and that was all the chains, tensioners, guides, gaskets, and a new coolant pipe. Good Luck with the sell but I would just fix it and keep it. If you replace everything it will be like a new motor. The LS usually doesn't have bottom end problems there problems usually come from the timing assembly.