Do games workshop buy used models?

Games Workshop does not buy used models.

They are a company focused on selling new models and supporting their own products. While there are many online marketplaces and hobby shops where you can buy and sell used models, Games Workshop is not involved in this.

However, Games Workshop does have a trade-in program for certain items, like older edition rulebooks and boxed sets. You can find more information about this program on their website or by contacting your local Games Workshop store.