Sorry to say it's not easy to even suggest a price since they have become so incredibly rare & with parts supplies almost non-existent condition & healthy running becomes a HUGE factor, as does finding the right buyer since most people have never seen one for the last 20 yrs & have forgotten their existence so few are looking.
Having been cheap to start with few were well cared for and their lightweight construction and high-revving engine made them highly susceptible to rust & damage .
At least they are distinctive & tiny enough to be memorable when seen these days.
I know one insurance company proposed $1700 for a good, registered '73 Z360 hardtop but rarity & condition makes values HUGELY variable.
'79 Accord, '89 CR-X SiR, '81 Prelude, '74 Z360 H/T, '71 Z360, '64 S600, '75 Lancia Beta.