I'm not gonna lie, this is an odd item with an equally odd history. You could only get this by ripping out and mailing one of the scratch and sniff cards in the back of the EarthBound Player's Guide that came bundled with the game in big box format. You were supposed to scratch the card, sniff it, and guess correctly what the mystery smell was. It was supposed to be "pizza" but it didn't matter what you wrote in because they sent the air freshener to everyone who mailed in. I managed to find some scans of the cards.
The air freshener smells like pizza and is based off the in-game pizza delivery service, Mach Pizza. It is really a cool, interesting item and I can't help but wonder how many of them are still floating around. I'm sure not many but keep checking eBay and be prepared to shell out around $300 if you want one. EarthBound items are a hot commodity right now and I will continue to report on what people are willing to pay for 20 year-old air fresheners.