Did a bit of clicking on websites and it seems that B&H is a fair bet. Once you factor in postage I can buy four packs of 25 sheets for about $300. I'm also waiting to hear back from a UK seller about postage. Their initial cost was cheaper than B&H but postage from the UK is often quite expensive so we will see what happens there. I was hoping to be able to buy one pack locally just to check it out but it looks like I'll just have to bite the bullet and spend up.