If you are looking to buy the PayPal Here card reader for taking payments, whether new machine or second hand, think twice, just remember, once out of warranty, if the reader develops any technical issues, PayPal will only guide you with troubleshoot solution same as the manual and ask you to buy new one on their website.
I purchased one on last ozbargain deal and only used twice to check whether it is working or not. Then I just did not use it. Practically, it is in new condition. When I tried to connect the card reader again it shows red and green light blinking which means there is malfunctioning. I called customer support and they guide with troubleshooting solution which seems they already knew it's not gonna work then without hesitation, just ask to buy a new one on the Paypal site.
Basically, Paypal is selling a card reader machine that is going to break after one year and if you request for the aftersales service, there is nothing but asking to buy a new card reader from their site.
What do you expect? The product is out of warranty, they're not going to just give you a new one.
There are many factors that can kill the device if not used within a long period of time. Such as heart or moisture.