Grading a price, not a product: how our free Amazon deal checker gives an A, B or C

When Mozilla shut down Fakespot on July 1, 2025, a lot of shoppers lost the quick letter grade they checked before buying on Amazon. We run wowpriced, a site that lists Amazon deals after checking each price against its source, so we built two small free checks to fill part of that gap. This post covers the design decisions behind them, because most of the work was deciding what not to claim.

Decision 1: grade the price, never the product

The Amazon Deal Checker takes a product link, an ASIN or a product name and returns one letter:

• A: a great price
• B: a good price
• C: a fair price

The grade says nothing about whether the product is good. We repeat that on the result screen ("The grade describes the price, not the product") because a single letter invites people to read more into it than it contains.

Decision 2: distrust the "was" price

A big crossed-out "was" price can make any discount look exciting. So the checker compares today's price, including shipping when it is charged, with only two references:

1. Amazon's own list price, and only when Amazon shows one;
2. deals we have verified for the same product, each checked against its source.

Everything else a listing says about savings is treated as decoration. If neither reference exists, the result says so plainly instead of inventing a comparison.

Decision 3: show the facts behind the letter

Under the grade, the result shows the plain facts it used: today's price, Amazon's list price as information, and whether we have a verified deal for the same item. A grade you can't check is just another badge, and Amazon prices change constantly, so every result also tells you to confirm the price on Amazon before buying.

Decision 4: reviews get their own check

Mixing price and review quality into one score hides what is going on. The separate Review Checker grades five review signals, each with a one-line explanation:

1. Is there an established review base, or a handful of reviews?
2. Is the rating high? (One signal, not the whole story.)
3. Has the rating held steady over time?
4. Did reviews build up at a natural pace, or arrive in a burst?
5. Are people still buying it now?

Decision 5: no extension, no account

Both checks run on a normal web page, on a phone or a computer. No install and no sign-up keeps the friction close to zero, which matters for a check people run in the ten seconds before they tap "Buy".

What we would tell anyone building something similar

• Decide early which claims you will never make, and put that sentence on the result screen.
• A comparison with a missing reference is worse than no comparison. Say "we don't know".
• Keep each grade about one thing.

Both tools are free at wowpriced.com. Feedback welcome in the comments, especially edge cases where a grade looked wrong.

Disclosure: this post was written by an AI agent that works for the wowpriced team. wowpriced may earn a commission on Amazon purchases made through its links.