Sonic the Hedgehog 3 and Sonic & Knuckles were planned as one game. A 34-megabit cartridge with save memory would have cost too much, and Sega of America had a McDonald's Happy Meal promotion booked for February 1994, so Sega Technical Institute split it in two. Sonic 3 came first, on February 2, 1994, and introduced Knuckles. Sonic & Knuckles followed on October 18 with a flap on top of the cartridge, and plugging Sonic 3 into it makes Sonic 3 & Knuckles, the full game, with Knuckles playable in the Sonic 3 levels. Together the two sold four million cartridges. A complete set means both carts, both boxes and both manuals, so count what's in the photos.
Before you plug it in
Should come with it
Check the listing photos against this list, and ask the seller about anything you can’t see. A missing piece should come off the price.
Sonic 3 saves to FRAM, so a dead save battery isn't a worry here. The parts unique to this pair are the Sonic & Knuckles flap and the connector under it, so look closely at those in the photos.
New to retro hardware? How to check a used retro console covers testing, yellowed plastic and opened shells, and regions and video out explains what will run on what, and on which TV.
Buying guide
The full Sonic 3 & Knuckles takes two carts, and we'd pair the Sonic & Knuckles titled tested at $37 delivered with the $28 loose Sonic 3, about $65 for both. There are at least 153 listings across the two games, and the $35 to $65 band mostly reflects loose carts; complete-in-box copies ask $94 for Sonic & Knuckles and up to $125 for Sonic 3, with one Sonic 3 CIB auction at $49 that will climb. Sega never put both games on one cart, so a single cart titled Sonic 3 & Knuckles is a reproduction, and on the real Sonic & Knuckles look closely at the flap on top and the connector under it. Sonic 3 saves to a FRAM chip, so there's no battery to die. Skip the Sonic 3 copies from sellers with no feedback shown.
$27.58est. delivered
The lowest delivered real cart here at $28, a loose Sonic 3 with the Mega Hit Series label in the photo. It isn't titled tested, but it saves to FRAM, so there's no save battery to worry about.
SEGA Sonic the Hedgehog 3 Sega Genesis Platformer KA NTSC-U/C Cartridge
$37.00delivered
A Sonic & Knuckles cart titled tested at $37 with free shipping, under the $43 median. Lock a Sonic 3 on top and you have the whole game, and the photo gives a clear look at the flap.
Sonic and Knuckles Sega Genesis Addon Cartridge Only Tested Ships Free
Delivered prices include shipping as eBay quoted it to a US address on Oct 15, 2026. Many sellers charge by distance, so your total may differ. eBay shows yours before you pay.
Snapshot
Checked . Some may have sold.
Delivered prices include shipping as eBay quoted it to a US address on Oct 15, 2026. Many sellers charge by distance, so your total may differ. eBay shows yours before you pay.
Used$27.58est. delivered
$22.00 + $5.58 shipping
Buy It Now$22.00
This seller takes offers, and many sellers accept less than the asking price.
Fine if you might miss it? Send an offer first. Someone else can still buy it while you wait for a reply.
Want it for sure? Use Buy It Now.
Good buy
Sonic 3 cart only, with the Mega Hit Series label in the photo. No test claim.
Seller: sstxlove33
99.2% positive
Used$37.00delivered
$37.00 · free shipping
Buy It Now$37.00
This seller takes offers, and many sellers accept less than the asking price.
Fine if you might miss it? Send an offer first. Someone else can still buy it while you wait for a reply.
Want it for sure? Use Buy It Now.
Good buy
Sonic & Knuckles cart only, titled tested.
Seller: buddygunnervintage
100% positive
Used$35.16est. delivered
$28.99 + $6.17 shipping
Buy It Now$28.99
This seller takes offers, and many sellers accept less than the asking price.
Fine if you might miss it? Send an offer first. Someone else can still buy it while you wait for a reply.
Want it for sure? Use Buy It Now.
Our take
Sonic & Knuckles cart only. No test claim.
Seller: evergreen5206
100% positive
Used$49.34est. delivered
$39.99 + $9.35 shipping
Auction · no bids yet · ends in 14h 35m
Our take
Sonic 3 complete in box. Auction with no bids yet, so it will climb.
Seller: collectorsed20
99.6% positive
Used$93.75est. delivered
$84.95 + $8.80 shipping
Buy It Now$84.95
Our take
Sonic & Knuckles complete in box.
Seller: stone_age_gamer
99.9% positive
Used$41.30est. delivered
$31.95 + $9.35 shipping
Buy It Now$31.95
Check the seller
Sonic 3 cart only, titled tested and working, Mega Hit Series label in the photo. No seller feedback shown.
Seller: Seller on eBay
Check feedback on the listing
Used$44.94est. delivered
$34.95 + $9.99 shipping
Buy It Now$34.95
Check the seller
Sonic 3 cart and case, no manual. No seller feedback shown.
Seller: Seller on eBay
Check feedback on the listing
Used$124.99delivered
$124.99 · free shipping
Buy It Now$124.99
Priced high
Sonic 3 CIB with case, manual and insert, at the top of the CIB asks.
Seller: near1
100% positive
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