Seems 2x overpriced to me considering the condition. btw, the top tubes on those Kogas are on the short side. Re: 6'1" on a 54cm, what is your PBH?
@
RiddleOfSteel pointed me to this n.o.s. 1992 Exerciser 58cm frameset (54.6cm TT) a while back as the geo aligns nicely with my long legs and short torso:
https://www.ebay.com/itm/Koga-Miyata...AAAOSws7hdh4vb
...assuming the smaller models share this form