It would be good whenever someone is planning a trip. Waze App lists the nearer gas stations along the entire route, but sometimes you are planning to refuel at a specific location and not every gas station there is shown.
It would be nice if you could edit gas price in WME, too. Some gas stations in remote locations don’t get price updates through the Waze App, but for example in Brazil, the National Oil Agency has a site that makes public the price of the gas stations in a regular basis, and even if it is not as accurate as seeing the price into the station, it’s better than having an outdated price when you search for it.
I would be in favor of visibility of gas prices through the live map, but I would be opposed to the ability to edit prices.
One of the reasons that I stopped using GasBuddy was because of the horrible inaccuracy. I could sit at my desk watching one of my traffic cameras, and see a station updated with the incorrect price, generally a stale price where the user was sitting at home updating prices to rack up worthless points. Likewise, I would see 10 or 20 stations in the area all updated by the same user within a 10 minute time period.
This may not be such a problem in other countries, but in metropolitan areas in the US, it would be. One of the things that I really like about Waze is that the user must at least be present at the gas station at the time he sends the price update.
I got your point about the problem of point hunters. About them, from my years in different online and offline communities, you can say for sure it’s a cat-mouse situation. You stop them from doing something for the points, they find another way to earn. If you go bold against them, you may create so much difficulty that even legitimate members of the community feels unwelcome and simply go away.
For online editing gas prices, the solution is simply restrict this feature to L3 or L-something the community feels comfortable with. Just like house numbers forcing is restricted.
As for the App, when you say that the user must be around the gas station to update it’s price, I can think of at least one easy way to fool the App and allow me to update any gas station I want. And it’s right there in Play Store (and possibly Apple Store too) to download.