If you book through a corporate TA they should be able to calculate exactly the price difference at the time or even historically. You can then pay the difference with a personal card.
Have never actually done this yet as every time I have wanted to do it the fare difference hasn’t been within the range I was willing to spend. But in theory it’s doable.
My company policy is for Premium Economy on an overnight return from the US. I value the better meal (and genuinely think there is quite a difference on BA) but can’t sleep unless flat so it’s no different from Economy as far as that side of things goes.
I figure the company has made the decision that us starting the next day of work with a good night’s sleep is simply not worth the four-figure per person price difference. To be honest, your workers have to pull in quite a lot of value to make this worthwhile. I am in a role that costs my company money rather than generates profit, so it is not much use complaining and I am inclined to agree with them.
Why does such a role exist?