We've been asked if it's possible to pledge for more than one reward, and if it's possible to get more than one of a single reward. Kickstarter only allows each backer to make a single pledge. But you can pledge more than the reward amount. There's more info on the Kickstarter FAQ section https://www.kickstarter.com/help/faq/backer+questions?ref=faq_nav#BackAProj
If you want to pledge for 2 T-shirts, double the amount of your pledge and still press the T-shirt reward button. After the campaign ends, we will take details from you about the number and size of T-shirts. But don't do this for the limited edition rewards - such as the sculptures - as even if you put in a higher pledge amount, Kickstarter records just one off the tally of that limited edition. We have no power to change it! For those very limited items, we only have the number shown so we'd still only be able to send you one item.
Hope that helps! If not - check out the Kickstarter FAQ page or ask us a direct question using the "ask the creator" option.