1970 on
Pens from the decades after the ballpoint took over, when people bought a fountain pen because they wanted one. Resin bodies, cartridge and converter fillers and the long-running flagship lines all belong here, from the Pelikan Souverän and Montblanc's resin Meisterstücks to Pilot's Custom range. Many are still in production, so used ones sit next to new ones on eBay. That's good news for buyers, because a well-kept used example can stand in for a new one, but check the details that changed between generations before you pay for an older one.
13 pens we cover.

Montblanc · 1952–present
PistonPrecious resin, 1980s
Modern
$525–$775 typical ask
29 on eBay

Montblanc · c. 1968–1978
PistonPiston-filling 22x series, 1970s
Modern
$130–$230 typical ask
25 on eBay

Montblanc · 1980s–early 2000s
Cartridge and converterSlim cartridge pen
Modern
$270–$380 typical ask
39 on eBay

Sheaffer · 1976–1998
Cartridge and converterMatte black, gold-plated trim, Classic size
Modern
$110–$200 typical ask
11 on eBay

Pilot · 1992–present
Cartridge and converter14K size 5 nib, cartridge or converter
Modern
$140–$210 typical ask
26 on eBay

Pilot · 2000–present
Plunger (vacuum)Plunger filler, 14K size 15 nib
Modern
$480–$600 typical ask
27 on eBay

Pilot · 1971–1980
Cartridge and converterModel M-350SS, integral steel nib
Modern
$230–$360 typical ask
28 on eBay

Pilot
Cartridge and converterModern
$30–$55 typical ask
12 on eBay

Pelikan · 1982–present
PistonGreen striped, old-style trim, 1982 to 1997
Modern
$290–$380 typical ask
27 on eBay

Pelikan · 1987–present
PistonBlack, old-style trim, before 1997
Modern
$500–$750 typical ask
17 on eBay

Pelikan · 1985–present
PistonSteel nib, old-style trim, 1985 to 1997
Modern
$140–$250 typical ask
27 on eBay

Pelikan · 1985–present
PistonOld-style, M400-sized, 1985 to 1997
Modern
$350–$525 typical ask
16 on eBay

Pelikan · 1997–present
PistonBlack, two-chick logo, 1997 to 2003
Modern
$900–$1,200 typical ask
26 on eBay