Earlier quoted context omitted.
Are you sure it actually cost your insurance $6k? Usually they have a high rack rate and negotiate down.
PrEP was pretty expensive. It cost the NHS about £5000 per year in 2017.
PrEP should be really cheap (~£10/mo) but the generic status of Truvada (emtricitabine and tenofovir) is being held up by legal shenanigans, so the NHS tariff price is currently £355.73/mo for the branded formulation. This has obviously severely constrained availability on the NHS, so a lot of at-risk individuals are just buying the generic online.