Buy one, be miserable because you don't have a spare. Buy two, be miserable because you're unsure if you picked the right two. Buy three, one of each style, but not spares of each style Forget four or five, buy 6, have pretties to look at, AND one of each style to play with!
Or, you can buy 3 of them, use one, save one as a safe queen and keep the third one for about 6 months and sell it on the exhange for an inflated price to help pay for the 2 you are keeping <img src="/ubbthreads/images/graemlins/grin.gif" alt="" />
Or you can buy 3, wait 6 months, sell the other two and you have a free knife.