NO
GSP applies to goods coming from the USA, nothing to do with double taxation.
Even within Canada used goods are taxable. If you buy a used car from a car dealer, you pay tax on the purchase price. Whether the car is new or used does not matter. The same is true when you buy goods are Value Village (for example) where most goods are used.
Some exceptions exist for exempt organizations (non-profit or religious) such as Trift stores operated by Salvation Army, St-Vincent de Paul, etc... where the price paid for goods is considered a donation. But those are the few exceptiions. The majority of taxable items are taxed, whether used or new, when imported or purchased from a GST/HST registered seller/merchant.