As in most cases it depends why you want it. As others have said, the S&W commemoratives rarely sell at a premium. On the other hand, they're the same quality from the same workmen and factory so if the price is right why not buy them? I wouldn't pay a premium for the 544 for example but having a 44-40 to shoot at less than the price of many other N frames seems ok to me especially if you want a S&W 44-40; how many of those are floating around in any configuration?
Someone above mentioned the Colt 1911 WWI Commemoratives. One of the best deals around, or were, if you wanted a pre-1970 Colt in 1911 configuration for under $1k. Try and buy the non-commemorative version for that price yet it is the same quality, same factory, same workmen.
If you're buying for investment opportunity I'd buy commemoratives only if available at a substantial discount from market prices.
Jeff
SWCA #1457