The rulebook says in the "Consume" section:
Each consume power can be used only once in a consume phase. Some powers allow multiple goods, “up to” some number, to be discarded, with each good producing an effect. Such powers must be fully used, if possible, when invoked.
Thus, a player with a tableau containing three novelty goods, New Vinland, and Free Trade Association, cannot consume two goods using FTA’s power (to consume up to 3 novelty goods for 1 VP and a card apiece) and then, based on the cards received, decide to consume the third novelty good using New Vinland’s power (to consume a good for two
Let's consider a slighty modified example: The player has a tableau containing two novelty goods, New Vinland, and Free Trade Association. Since FTA power cannot be fully used because the player does not have three novelty goods, the player decide to use it to consume just one novelty good. The rules above do not forbid that. Then the player uses the New Vinland power for the remaining novelty good.
If the rules intention was to forbid that, they would say instead of "Such powers must be fully used, if possible, when invoked" something to the effect "Such powers must consume as many matching goods as the player has, up to the specified number".
Did I get this right? I'd like an authorative source, please.