From their announcement:
Just added some new models to the shop. The first up is the Goblin Catapult. It costs £8 and comes with 3 crew. I've also added the wheels separately at £1 for 4. Along with this are the Goblin slave crews from the catapult and the bolt thrower as separate shop entries. These are priced at £1 for 3. All the models are resin.