Article or no article: “at the price of a higher workload”?

Question

The finer points (the infamous 10%?) of when to use indefinite articles still manage to elude me sometimes. Does the article "a" belong in the following sentence or not?

However, [foo] yields [bar] at the price of a higher workload for [baz].

Bonus question: Which rule applies here?

Answer 1

The object of the preposition ("workload") is singular, so yes, the article works there. If you were speaking of a quantity, however, you wouldn't use the article:

... at the price of more working hours for [baz].