I always combine packaging, if this doesn't happen automatically at checkout then message me and I will send a combined invoice. Postage costs only increase if the increase in weight pushes it above the threshold for Royal Mail (100g, 250g, 500g, 750g and 2kg).

I understand the importance of good packaging and make sure everything I send is packed how I would want to receive it. I'm downsizing my collections, slowly sorting through my huge bits boxes and helping my friends in our gaming group sell their oddities. I'm a collector and wargamer myself (and a massive Blood Bowl fan).