My D90 is probaly coming this week and im going to need a memory card. I searched google and found out the Sandisk extreme are the best cards but here in Canada they are around 100$. What capacity of memory should i be running? There is a 4gb here: http://www.bestbuy.ca/catalog/proddetail.asp?logon=&langid=EN&sku_id=0926INGFS10081602&catid=20093 I dont want to spend more than 50$ really, and sorry if this thread has been done. Ive searched it and nothing came up.