Moral value is the most basic expression of value that is sharable. It is almost always factionally defined. It is probably the best definition of a faction to say that its members "share some moral values".
When someone uses a phrase like family values they are probably referring to a certain set of moral values they learned in their own family, and not to anything objective or necessarily applicable to anyone else's family, for instance.
Even just using a phrase like moral purchasing assumes that some moral value can be agreed on by some group, that can be expressed by some system that group uses. See institutional buying criteria for the most concrete idea of this.
Accepting some reduced price value as expressing a higher moral value is the thinking behind the price premium. There are ideologies that consider this to be itself immoral, as the market mechanism is supposed to somehow reflect the sum of all such choices collectively made by all others in the market, a collective moral valuation that one would be a fool to resist or attempt to redefine. However, as Gandhi put it, you may think that what you do is very little, and so it may be. But it is very important to do it anyway.