Maybe one last shot at this: When you take the sentence in isolation, you have to give some weight to the introductory prepositional phrase. But if it's from a news article, as you say, the "shrinking hours and rising food costs" may have already been thoroughly discussed. The author may have considered this a bridge, or transition to the gas price thing, wishing to show the connection but not intending to emphasize it.
He might have said, "And furthermore, gas prices are - - - - - as he drives etc."
Or, "Shrinking hours and rising food costs are not the only problem. Gas prices are - - - - - - as he drives etc."
Or, "In addition to shrinking hours and rising food costs, here's another item. Gas prices etc."
IMHO the error is in constructing the sentence in a way that makes hours and food part of the subject.
Something that's new to me here at EF is the approach of treating long constructions as modifying other long constructions. If you take the approach that "In addition to shrinking hours and rising food costs" modifies everything which follows, instead of just the subject, my objection seems to melt away. What do you think?