Sharing an ROI calculator for choosing which games to add for card-farming (Excel + Python)

[cardroi-calc]

I've been using ASF for card-farming and got tired of guessing whether a given $0.49-$5 game would actually pay itself back in cards. Built a small Excel + Python kit, sharing it here in case it's useful to anyone else here.

What it does

• Excel workbook: paste an AppID + your buy price → instant ROI / Profit / Loss verdict per game. Handles Steam Market's 15% fee, default 50% drop rate (configurable in Settings sheet), foil exclusion. 50 games per sheet with conditional formatting (red = loss, green = profit, yellow = breakeven).
• • Python script: one command (python update_prices.py) pulls live game names, set sizes, and median card prices straight from Steam Store + Community Market APIs. ~2 min for 50 games. No Steam API key required.
    The math

Net  = Set_Size × Drop_Rate × Avg_Card_Price × (1 − Fee)
ROI% = (Net − Buy_Price) / Buy_Price × 100

A game pays itself back in cards if Buy_Price < Net. Tuning fee + drop_rate in the Settings sheet lets you model different scenarios (full-set drop accounts, Steam events, etc.).

Numbers I'm seeing on a fresh scan today (real Steam data)

Game	Set	Avg card	Expected drops	Net
Terraria	9	$0.08	4.5	$0.31
Vermintide 2	10	$0.05	5.0	$0.21
Undertale	5	$0.16	2.5	$0.34
Anno 1800	9	$0.05	4.5	$0.19

So if a game is on sale for ≤ $0.20, Undertale or Terraria would clear net positive purely from cards. Free packages via ASF's FreePackages plugin are infinite ROI.

Why post here

Looking for feedback on what other columns / mechanics would actually be useful to ASF users — currently considering: foil ROI separately, gem-conversion path (cards → gems → boosters → cards), per-region Steam pricing import, badge-completion bonus modeling.

Links

• Landing page with screenshots: https://cardroi-steam-cards.surge.sh
• • One-shot delivery via TG bot if you want the ready-to-run ZIP instead of building it yourself: @cardroi_sales_bot (6.99 USDT TRC20)
• • Happy to share the bare formulas / a free preview xlsx if a mod considers the above too commercial — DM me here
    (Mods: feel free to move this to Offtopic if General isn't the right place. Open to any feedback on framing.)

[nolddor]

Trying to sell your software:

On a non-profit / open source project is far from ideal.

[cardroi-calc]

Fair feedback, but I'd push back on the framing.

The discussion above is value-first by design: the formula, the math walkthrough, and four games' worth of real Steam-API numbers are all in the post itself — anyone reading can take that and roll their own sheet in 10 minutes (the README spec follows the table I posted, nothing hidden). The bot link is the last item under "Links", explicitly framed as one delivery option for people who'd rather not build it themselves.

ASF being OSS doesn't, to my read, forbid mentioning a related paid tool — JustArchi's own README lists "Steam donate" alongside the Discord link, and the General category isn't pinned with a no-commerce rule. Plugin authors charging for tooling is also a known pattern in this ecosystem.

If the consensus from this community / mods is "don't ever mention a paid option here," I'll happily edit the bot link out and keep the post as a pure math share. But I don't think the right move is to retract everything because one commenter dislikes the footer.

Genuinely curious which part you'd want to see different. Is it the bot link existing at all, or the post being heavier on the tool than the math?

[JustArchi]

There's no need to act as if "math walkthrough" you're mentioning was something that AI wouldn't give you in 5 seconds upon asking "how to calculate ROI from steam card drops, taking price of the game into the account".

But it's okay to leave this topic here, it won't be removed on its own as it doesn't break any rule, and it's not my intention to forbid people from ever posting related tools, even if they're paid, as long as it benefits community and is not classified as harmful towards the main project. I moved it to offtopic though, as it's not general discussion of any kind.

[cardroi-calc]

Fair point on the math being trivially AI-derivable — you're right, I oversold the "walkthrough" framing. The pieces I figured were actually worth packaging are the filled xlsx (conditional formatting + 50-game layout) and the Steam API scraper that pulls set sizes + median card prices for the whole sheet in one command. That's the work I'd want someone paying for, not the formula itself.

Appreciate you keeping the topic up and moving it to Offtopic — that's a reasonable call, I'll be more careful with framing for related posts.

[cardroi-calc]

Followup: pushed the bare formula + a single-game lookup script to github.com/cardroi-calc/steam-card-profit (MIT). README is the math + sample numbers + a python card_profit.py <appid> <price> helper that pulls set size and median card price from the Steam Community Market API. That's the public reference now; anyone who just wants to check one game against the formula can use that directly without paying anything.