We've searched the internet and found the largest collection of O Scale trains for sale is on eBay. Below are the listings for 'F9'.

Williams Union Pacific F 9 Diesel Passenger Set
Williams Union Pacific F 9 Diesel Passenger Set
$71.01 (6 Bids)
Time Remaining: 22h 9m
LIONEL 6 16946 Chesapeake  Ohio F9 Well Car NIB 14 in FREE Ship Lower 48 States
LIONEL 6 16946 Chesapeake Ohio F9 Well Car NIB 14 in FREE Ship Lower 48 States
$34.99
Time Remaining: 23h 9m
Buy It Now for only: $34.99
LIONEL TRAINS 6 16983 PENNSYLVANIA RAIL ROAD F 9 WELL CAR WITH CABLE REELS
LIONEL TRAINS 6 16983 PENNSYLVANIA RAIL ROAD F 9 WELL CAR WITH CABLE REELS
$35.99
Time Remaining: 1d 20h 23m
Buy It Now for only: $35.99
LIONEL 3840 CHESAPEAKE  OHIO F9 WELL CAR  16946
LIONEL 3840 CHESAPEAKE OHIO F9 WELL CAR 16946
$26.68
Time Remaining: 1d 23h 1m
Buy It Now for only: $26.68
ATLAS O SCALE F 9 PENN CENTRAL F7A DIESEL LOCOMOTIVE CUSTOM WEATHERED CONRAIL
ATLAS O SCALE F 9 PENN CENTRAL F7A DIESEL LOCOMOTIVE CUSTOM WEATHERED CONRAIL
$250.00
Time Remaining: 1d 23h 11m
Lionel O Scale PRR Pennsylvania F9 Well Flat Car 3R
Lionel O Scale PRR Pennsylvania F9 Well Flat Car 3R
$27.50
Time Remaining: 2d 20h 49m
LIONEL 16318 LL FLATCAR 16929 BC GONDOLA  16946 CO F9 WELL CAR ALL W REELS
LIONEL 16318 LL FLATCAR 16929 BC GONDOLA 16946 CO F9 WELL CAR ALL W REELS
$94.00
Time Remaining: 8d 46m
Buy It Now for only: $94.00
Lionel 6983 Pennsylvania Rail Road F9 Well Car W Cable Reels 6 16983 1997 C 9
Lionel 6983 Pennsylvania Rail Road F9 Well Car W Cable Reels 6 16983 1997 C 9
$49.00
Time Remaining: 8d 19h 59m
Buy It Now for only: $49.00
Lionel 6 16983 6983 Pennsylvania RR F9 Well Car NIB Brand New C 10 O scale
Lionel 6 16983 6983 Pennsylvania RR F9 Well Car NIB Brand New C 10 O scale
$40.00
Time Remaining: 8d 21h 34m
Buy It Now for only: $40.00
+ATLAS 6103 F 9 CHESAPEAKE  OHIO DIESEL LOCO MIB 2 RAIL
+ATLAS 6103 F 9 CHESAPEAKE OHIO DIESEL LOCO MIB 2 RAIL
$99.95
Time Remaining: 11d 18h 1m
Buy It Now for only: $99.95
Lionel new 6 16946 Chesaapeake  Ohio F9 well car
Lionel new 6 16946 Chesaapeake Ohio F9 well car
$40.00
Time Remaining: 12d 13h 48m
Buy It Now for only: $40.00
Lionel 6 16983 Pennsylvania 6983 RR F9 Well Car w ob
Lionel 6 16983 Pennsylvania 6983 RR F9 Well Car w ob
$44.95
Time Remaining: 23d 17h 27m
Buy It Now for only: $44.95
Lionel Pennsylvania 6983 F9 Well Car 6 16983 NIB
Lionel Pennsylvania 6983 F9 Well Car 6 16983 NIB
$39.99
Time Remaining: 28d 20h 19m
Buy It Now for only: $39.99

Other O Scale train items recently purchased through this site:

Williams Union Pacific F 9 Diesel Passenger Set
+ATLAS 6103 F 9 CHESAPEAKE OHIO DIESEL LOCO MIB 2 RAIL
LIONEL 3840 CHESAPEAKE OHIO F9 WELL CAR 16946
Lionel Pennsylvania 6983 F9 Well Car 6 16983 NIB
Lionel new 6 16946 Chesaapeake Ohio F9 well car
ATLAS O SCALE F 9 PENN CENTRAL F7A DIESEL LOCOMOTIVE CUSTOM WEATHERED CONRAIL
Lionel 6 16983 6983 Pennsylvania RR F9 Well Car NIB Brand New C 10 O scale
LIONEL TRAINS 6 16983 PENNSYLVANIA RAIL ROAD F 9 WELL CAR WITH CABLE REELS
Lionel 6 16983 Pennsylvania 6983 RR F9 Well Car w ob
Lionel O Scale PRR Pennsylvania F9 Well Flat Car 3R
LIONEL 16318 LL FLATCAR 16929 BC GONDOLA 16946 CO F9 WELL CAR ALL W REELS
LIONEL 6 16946 Chesapeake Ohio F9 Well Car NIB 14 in FREE Ship Lower 48 States
Lionel 6983 Pennsylvania Rail Road F9 Well Car W Cable Reels 6 16983 1997 C 9