Academics... what are the ethics of splitting costs on travel for two interviews?

Miscellaneous and Personal Stuff I Must Share
1

Wordy title I know, but I’d love some advice.

I’m heading to a conference out of state, which happens to be the state where I’m two job searches. School A called last week and I will interview and do a job talk after the conference. School B called yesterday and wants to interview on the front end of the conference. I told School B that I am interviewing with School A after, but I’m still interested in their position.

Of course I already made travel plans for the conference, so School A volunteered to pay for the cost of changing my plans. They work on the reimbursement system. Now with School B in the picture, I need to change the front-end of the plan as well.

Should I split the bill of the entire trip in half and ask School A and School B to pay for half each? Or something else? What are the ethics of splitting costs on one trip?

(Obviously this is a minor dilemma, but I’m procrastinating…)

2

I can see how it seems unfair to have one school pay the whole plane ticket, but it probably won’t work any other way. They’ll need to have receipts for reimbursement, and you can’t factor in what percentage each one pays. Suppose you didn’t have the conference, then each of them would end up paying the full trip anyway. So I can imagine a scenario like this: School A pays for a one-way ticket from your city. Your department pays for transport from there to the conference. At the end of the conference School B pays for transport from there, plus back to your city. Alternately, school A pays for a return flight, and school B pays for your travel from the conference city, then back to city A.