Second hand hardware wallets are generally a bad idea. There was a well publicized case at the start of this year of a reddit user who used a second hand device that had been pre-initialized and had all their coins stolen, and this is not the only example. You can read about it here: https://www.ledger.fr/2018/01/12/scam-second-hand-ledger-device/

For the sake of $99, it's not worth the risk of losing all your coins. If you are using a second hand Ledger, then first make sure it is a genuine device by following the instructions here: https://support.ledgerwallet.com/hc/en-us/articles/360002481534-Check-if-device-is-genuine. Ensure you update to the latest firmware, and always initialize the device yourself and write down your own seed.

I'm not saying this is a scam, just that many people have been scammed by second hand devices before. Be careful.