If that's the downside of Anesthesia being legal, you need to also weigh the benefits on the scale. I imagine it would probably be much cheaper & easier to get, therefore it would be more widely used and many more people could avoid pain if they wanted to.
Good point; I agree that the expected benefit is an equally relevant fact.
http://www.theverge.com/2012/8/8/3177438/cyborg-america-biohackers-grinders-body-hackers