I bought second hand because I couldn't afford to pay brand new, I've finished pumping now but it got me through my journey well
I bought Elvie new and second hand main spectra pump which I bought new replacement parts for so I knew the parts the milk went through were new and was still much cheaper than a new machine. Possibly could do similar with a wearable one too replacing the necessary parts you aren’t comfortable with!
To be honest it depends, I got some momcozy s12 pro second hand and I could feel the suction power being different from one to another. But I also got a medela freestyle and it's been brilliant