Wow, cool double covers fellows.. Just a couple of questions about them since I've never owned one yet.. But, how much is the price difference between a double cover and a regular single covered book? Is there a significant difference in the value? Does it vary between GA, SA, BA, etc.? Also, when CGC'ed, do they take the front cover's condition and give it that grade or do they avg. the 2 covers out or take the double cover's condition's grade? Sorry if these have been answered in previous posts. Thanks!