It depends on if the wall is load bearing or not, and how much electrical, plumbing, and HVAC might be in it. Also, your foundation type and how you plan to handle the repair work on the floor and ceiling. 7-15K, would be about average here, and unless you are in a higher labor market than me (Miami, etc.) you should be in the same ballpark. You will be required to have structural drawings for your local building office for permitting sake, and you will need a permit for both the wall removal and the elevator installation. IF that elevator would be allowed as code compliant. In many jurisdictions it's not as the safety mechanism to keep it from crashing during a power outage aren't considered sufficient.