Why does Shopify Plus look so cheap on apps?

It doesn’t, it looks expensive. The calculator allocates $18k/yr (under $25M GMV) or $36k/yr (above) for Plus apps, which is $54k, $108k over 3 years. That’s the highest extension/app line of any platform in the model.

If you’re seeing a lower number than your actual app spend, common reasons:

• Subscriptions stack adds fast. Klaviyo ($1k+/mo at scale), Recharge / Bold Subscriptions (~$500, $2k/mo), Loop Returns (~$700/mo), Yotpo / Stamped (~$300, $1k/mo), Gorgias / Re:amaze ($300, $1k/mo), Tapcart or Shop App customisation. A typical D2C Plus stack runs $3k, $5k/mo total, the calculator is conservative at $1.5k, $3k.
• Plus Functions developer time isn’t in the app line. It’s in the “dev ongoing” bucket. If your Functions developer is contracted at $75/hr and you have ~5 hrs/wk of Functions work, that’s another $39k/yr.
• Shopify Markets adds 1.5% on cross-border transactions. Calculator doesn’t separate this from the 0.15% per-tx fee.

If your actual Plus app spend is above $5k/mo, add the delta to the calculator output manually. The relative ranking still holds.