That depends on several factors. 14k gold means that the gold content is .583% pure gold with other alloys added to make the metal harder, usually copper. However, only a portion of the weight of a pocket watch is the case.
The movement, metal reinforcements, hands, crystal, winding stem, hinges, etc. are almost always other metals. And every watch is different when it comes to how dense or heavy the case is. Some general percentage weights for antique pocket watch cases are as follows;
14k gold Hunter cases are between 38% to 50% with 40% being average
14k Open faced cases are between 30% to 45% with 35% being average
Silver Hunter cases average around 70% of the total watch weight
Silver Open Faced cases average around 65% of the total watch weight.
So a 14k gold hunters watch (not gold filled or rolled) that weighs 100 grams would have approximately 40 grams of 14k gold, or 23.3 grams (.583 X 40) of pure gold.
So with an average gold prices ranging form $1150 -$1225, the example above would pay approximately $725.00 for the gold watch. That is 75% of the gold's spot value...