Just got back from out of town. Mi.ke - nice pickup on the Burnett! I honestly don't think it's rough (I'd take it in a second) - I'm a stickler for surface, but I've noticed the yellow background Chicles just don't have super clean surfaces - I tend to compromise on those. Was that why you thought its rough? Did you pick up the Johnsos too? My rule of thumb is 300 for a high numbered PSA 3, (guessing yours is similar) but in this case, I saw some wear, still was thinking 260-275 though. The Cadell PSA 4.5, Masterson, and Burnett were the "steals"/ones that bothered me - while I like getting deals - seeing the prices drop is a little uncomfortable.
How's your set going? Always nice to find out about someone else working on it. Do you have the Nagurski yet? Do you really consider a Burnett PSA 6 low grade? I think Jeff can tell you - those don't come around that often...
Jeff, good luck with the 7 - the only time I recall seeing high numbers graded 7 or above was with an AH, but I can't remember which one and there were actually several up at once. I guess I'll have to wait a little longer to get a look at your current Burnett (not the dup)