Just because it is new doesn't mean it will not leak. If it does leak in either case it is some orings, so as long as you have a few extra, you will be covered.
Also, You do not see a lot of these for sale for the same reason you want one. That may be why there is not a huge savings for getting a used one. For me $20 savings is $20 I can spend on entry and air, but to each his own.