In a sense, yes. While there are many, many factors that go into my decision for what gun I buy next, here are my main criterion (roughly in order of importance):
Note: this gun-buying guide operates under the assumption that I have both the financial means and the personal will to make a particular purchase, and that any candidates for any such purchase will fall within reasonable limits of affordability.
1.) Risk of Bannination/evaporation: for instance, instant priority is given to any guns that are in danger of running out due to a ban (guns affected by the barrel importation ban, for example) or guns that are not going to be produced/etc. anymore (like the Winchester 94 I just bought). The "evaporation" part of this factor also includes rare finds/unusually fantastic deals on guns. It is assumed that if one does not act nearly instantly on an incredibly well-priced firearm that the particular deal in question will "evaporate" soon.
2.) Quality/reliability/durability/etc.: make sure the gun you're buying is worth buying...basically, do your homework thoroughly. This criterion can be ruled null/void if the gun in question is being bought purely for historical/collecting reasons, and not to be shot.
3.) Firearms Diversity: don't buy three Garands when you could get a Garand, a K98, an SKS, and an Enfield for roughly the same price. Also applies to caliber/usefulness situations (i.e., don't have 4 rifles in .30-06 and nothing in .308, etc.).
4.) Usefulness: for example, don't end up owning twenty cool-but-useless rifles and basically nothing good for hunting or defense.
5.) Desire: what does my "gut" tell me that I just "want" the most? This is more of a wild card/tie breaker for when a gun agrees with one deciding factor but disagrees with another. Can overrule all other factors in extreme situations.