Metal Bands Merch

How are you guys getting bands merch. Is it on tour or from sites. Will the merch price increase during the tour? I'm currently trying to buy Sylosis merch. They're coming in November with Killswitch Engage. I'm not sure they'll have more options for merch during the show. Ordering from official store makes the shipping fee more than the tee. How do you guys get your merch in Australia?