I never check price guides...ever. VCP, SMR, MPH, LOL, LMK, FYI, or even SOL.
My focus is, and always has been, T206...after 25 years of collecting, I think I have a good sense of values. If something pops up and want a price opinion, I'll ask a friend or two, but never check price guides at all.
I watch a card, and if I want it, I bid. if I really want it, I bid strong. I bid up to what i'm comfortable spending.