Thanks! I'm planning to sell it with the PS2 cable mod, and Nubbinator's cable, so it can be used as-is. If no-one is interested in the PAC unit, I'll see if someone on eBay wants it for parts.
It's a beautiful keyboard, I can see now what all the fuss is about Dolch caps. If it just had some other kind of switch, I'm really not a MX Blue fan.
I think fair market value for an 1813HFX is still in the $80-120 range dependent on condition. No clue what the rest of the PAC is worth... if it was me I would probably just give it as an option with the condition they have to pay the additional shipping that would be needed.