$2700 for a 3,800 mile flight* in a flat bed is not really "this high" especially when you have zero flexibility on dates. I think you can probably do closer to $2000 on DFW-HNL if you plan well in advance and are flexible on dates, particularly if you can travel mid-week (e.g., Tues/Wed).

*This is longer than JFK-LHR which would normally be $3k-8k r/t but can go down to ~$2k for off periods.