I signed up with Going.com because I thought they offered that feature too. If it’s available, I haven’t been able to find it, and unfortunately, customer service wasn’t able to help either.
If Going sends you an email deal, it will be a bargain. However, the dates and conditions are usually strict. What I would do is click on the Going information and then double-check on Google Flights or Kayak or the actual airline website to confirm.
As pointed out, Google Flights will tell you if the fare you’re looking at is average, low, or high. And you can use the graph to look at past pricing.
But with so many fare options these days (basic economy, main, refundable or not, etc.) we all need to get in the habit of really researching before pulling the trigger and purchasing the airfare. It’s no longer a simple “click to purchase” decision if you’re wanting a deal. Of course, sometimes the hassle to save a few bucks isn’t worth it - like if UA, AA, Delta, and SW all have fares within $20-30 of each other, I’ll pick the best schedule with good connections instead of defaulting to the lowest price.