I see your a new member, welcome, now does that mean you are new to the car wash biz as well? If so I would prbly go with a new machine for the warranty offered and to learn how to run one. Once I had some time under my belt I think used is definitely a viable option.
I’ve bought numerous used machines. They were the same brand that I was already familiar with and had many years under my belt. If I was green or it was something totally different that I was use to, probably not.