Travel prices are strangely inconsistent

My character is an Imperial Pilgrim with the Lady sign, with 10 summons following him, notice how Vivec is the only destination that's consistent for some reason:

Morrowind.exe:

OpenMW:

With the mages guild:

Morrowind.exe:

OpenMW:

Worth noting that it looks like OpenMW has forced travel cost for "all passengers" instead of it being optional: c7ac06b9

Even with that forced, travel prices are still inconsistent with the equivalent MCP option used.