Steam Appraiser Firefox

Steam Appraiser

Professional price evaluation for Steam games and wishlists based on age, reviews, and market value
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Modify request and response headers. No ads, no malware.

Features & Capabilities

Professional price evaluation for Steam games and wishlists based on age, reviews, and market value

"Steam Appraiser" evaluates the price and grades of games based on their age, user reviews, and market value to help users make informed decisions about purchasing games. The calculator takes into account a game's potential lifetime and adjusts it based on user reviews to provide an accurate evaluation of the game's worth (deprecated values).

V1.4 release update: includes management of the Steam categories with different overlays, 4 theme, classic, glass (transparent), black marble, silver white (white glass). Overlays now can be resized and draggable.

Steam Appraiser is designed to help gamers avoid making impulsive purchases based solely on discounts. Instead, it encourages them to consider a game's actual worth before buying.

🏷️ Discount Ratings Not all discounts are created equal. Most of the time, editors are just returning the price to what it should already be. Here's how we rate them:

  • POOR — The discount doesn't even reach the deprecated price. Still better than full price, but maybe there are more honest editors than this one — check alternatives. (Above deprecated price + 5%)
  • FAIR — Most discounts are just editors returning the price to a normal deprecated price in a competitive market. Nothing grand or to be thankful about, this is around what should be the "normal" price. (Around deprecated price ± 5%)
  • WARM — This is under the deprecated price and it's an honest move to offer a real discount. (Below deprecated price by 5%)
  • NICE — This is a nice discount. (Below deprecated price by 20%+)
  • EPIC — Wow getting hyped... or not. (Below deprecated price by 35%+)
  • LEGENDARY — Difficult to find something discounted more than that. (Below deprecated price by 50%+)
📊 Grading System Games are graded from S+ (best) to F (worst) based on multiple factors: S+ / S — Exceptional and treasured. A+ / A — Very solid choice. B+ / B — Honest. C — Risky... U sure ? D — Poor value, check reviews? E / F / F- — Just walk away...

🔢 How It Works The estimated fair price is built on a dynamic depreciation model:

Game Age: Based on a ~7 year potential lifetime, using an exponential depreciation curve. Review Score: Praiseworthy games earn a longer lifetime (10–11 years), while painful experiences shorten it (4–6 years).

Global Review Count and community rating: Popular games maintain their value better. After reviews, "AAA studio rating" has been removed from the calculus — I didn't find any conclusive evidence about impact on lifetime and value.

💡 How to Use Browse Steam as normal The overlay appears automatically on game pages Check the grade (large letter) for an instant assessment View estimated fair price vs current price Click "Would you like to know more?" for the detailed breakdown Use Parameters to change visual style

⚙️ Features Multiple Styles: Standard, Glass, Black Marble, or Silver White themes Draggable: Move the overlay by dragging the header Resizable: Dynamic resize Compact Frames: See grades on wishlist and category pages Smart Detection: Handles free games, unknown discounts, and special cases International Languages: Working on expanding language support

⚠️ Limitations This is a mathematical model — even with a finer and flexible approach it will always have limits and will not keep up with exceptions and weird games.

  • Scraping by nature: This is a scraping tool. Even made resilient and adaptable, the scraping → parsing → calculating → grading pipeline can take time to refresh if you scroll at high speed.
  • Niche games may not follow standard pricing patterns
  • Regional pricing differences are not accounted for
  • Your personal value assessment may differ — and that's nice !

User Growth & Download Statistics

Manifest V3 Add-on
By:
Main Darkness
Daily users:
3 1
Version:
1.3.9 Last updated: 2026-02-28
Version code:
6161506
Creation date:
2026-02-25
Risk:
High risk impact Moderate risk likelihood
Permissions:
Host permissions:
  • https://store.steampowered.com/*
Content scripts matches:
  • store.steampowered.com
Size:
125.80KB
Email:
ma*****@gmail.com
Full description:
See detailed description
Source:
Firefox Add-ons Store
Data ingested on:
2026-08-02
Compare stats and ranking:

Contact the developer

Chrome-Stats does not own this Firefox add-on. Please use these information below to contact the Firefox add-on developer.
Developed by:
Main Darkness
Firefox Add-ons Store
https://addons.mozilla.org/firefox/addon/steam-appraiser/
Email:
ma*****@gmail.com

Is Steam Appraiser Safe?

Risk impact
Risk impact measures the level of extra permissions an extension has access to. A low risk impact extension cannot do much harms, whereas a high risk impact extension can do a lot of damage like stealing your password, bypassing your security settings, and accessing your personal data. High risk impact extensions are not necessarily malicious. However, if they do turn malicious, they can be very harmful.

Steam Appraiser requires some sensitive permissions that could impact your browser and data security. Exercise caution before installing.

Risk impact analysis details
  • Critical Grants access to browser tabs, which can be used to track user browsing habits and history, presenting a privacy concern.
  • High ******* ******* **** *** ****** ***** *** ***** ** ******* **** ********* ********* ** * *********** *****
  • High ******* ****** ** *** ********* ******** ****************
Risk likelihood
Risk likelihood measures the probability that a Firefox add-on may turn malicious. This is determined by the publisher and the Firefox add-on reputation on Firefox Add-ons Store, the amount of time the Firefox add-on has been around, and other signals about the Firefox add-on. Our algorithms are not perfect, and are subject to change as we discover new ways to detect malicious extensions. We recommend that you always exercise caution when installing a Firefox add-on.

Steam Appraiser is probably trust-worthy. Prefer other publishers if available. Exercise caution when installing this add-on.

Risk likelihood analysis details
  • High This extension has low user count. Unpopular extensions may not be stable or safe.
  • Medium **** ********* *** ***** ** *** **** * ******* *** ********** *** *** ** ****** ** *****
  • Low **** ********* *** ******* **** **** * ****** **** ***** ******** *** **** ****** ** ** ****** *** *****
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