I'm noticing that coin mags list only up to MS66. Is the reason because most people collector MS65 and lower? Prob I'd image.
Many things. One of the main ones might be what you describe. Some coins do not exist graded higher than 66, (some not that high). However, such price guides are useful somewhat for SCOPE, (is the coin worth $5 or $500), but they almost always have prices sky high. Please never use them for a purchase decision. You can search here where I have detailed numerous times the exact specifics why price guides are always high for low/medium priced coins.
You will rarely see prices listed for grades better than MS66 because these coins are harder to find. Even the Red Book does not list anything better than MS65. Chris
Problem is higher grades can vary greatly based on perceived eye appeal, so price guides on grades above 65 quickly become almost useless. Generally guides stop at 65 for precisely that reason. Quite often there's not enough (sometimes any at all) of a given issue that's ever graded that high, so there's not enough data to give a good estimation on value. Stopping at 65 seems safer for that reason. Above that, best I can say is check recent auction prices. If a coin is very rare in that grade expect to pay a significant premium over the 65 price. Some coins are so common in higher grades that it doesn't become a big deal until they hit 70.
