Round trip business (with a return 6 months later) was 2,530 Swiss francs. So I screenshotted the horrible one-way price to go in my expense report, and then booked the round trip ticket.
No, I was meant to book a one-way ticket, since I was moving offices. But I had to have evidence to show that booking round-trip was cheaper in case anyone questioned why I had purchased round-trip instead of one-way.