Last-minute travelers might be in luck as international airfares have plunged below $1,000 for the first time since mid-March – but experts are warning it will likely be just a brief respite as the effects from the war in Iran keep fuel costs elevated. The average international ticket dropped to $980 last week, the lowest level since the week of March 23, when prices hit $954, according to Kayak, which tracks weekly flight searches. Destinations…