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If they're in mint condition, perhaps the same as the new version runs for now. Roughly, $80 for the Endura, $70 for the Delica, $60 for the Dragonfly. If they're not mint, less than that. The new versions of these knives are better, and while some people do like to collect from the 90s, it's not exactly like FRN Spydercos have gold filigree or anything. You can check this stuff yourself by searching eBay, they should list what these old knives were sold for most recently.
I've never seen a folding knife record slip like that before. Are you required to register folding knives where you live or something?
Lost to the Ages: C90GRE Stretch 1 ZDP-189 British Racing Green | C28GRE2 Dragonfly 2 ZDP-189 British Racing Green
C12BK2W Matriarch 2 VG-10 Emerson Open | C81G2 Para Military 2 S30V
Currently Rotating: C81GPRGR2 Para Military 2 K390 Ranger Green | C223GPRGR Para 3 K390 Ranger Green
C90FPIV2 Stretch 2 Straight Spine, VG-10 Rit Dye'd Dark Apple Green | C223GP Para 3 S30V Green Canvas Micarta
C41BORE5 Native 5 Lightweight REX 45 Burnt Orange | C223BORE Para 3 Lightweight REX 45 Burnt Orange
C101GY2 Manix 2 Lightweight Maxamet Gray | C28GFG Dragonfly VG-10 Foliage Green
MT27 Mule Team 27 Micro-Melt PD#1 Ranger Green | C36GPGR Military 204p Dark Green