Turns out I have the flu. After posting yesterday, things went downhill fast. Still running a fever with acetaminophen in me.
Anyway, I've been able to sell many frames over the years -- some as complete bike -- and I've done so with the fork cut down and with some spacers above the fork. Some sales have been bargain basement prices, but others have been at market value. Generally staying upright helps bikes retain market value.
These days I figure that there are enough rising stems out there that you can cut down your fork reasonably (not slammed) and not run into resale issues. YMMV.
BTW, I don't intend to ever sell the Serotta.