| Workshop Rent |
Fixed |
Include $3,500/month in overhead for the relevant planning range. |
Spreading rent across units and hiding the true monthly hurdle. |
| Platform Subscription |
Fixed |
Include $299/month as recurring admin overhead from Month 1. |
Treating the subscription as a sales fee that rises with orders. |
| Year 1 Salary Base |
Fixed |
Include about $11,667/month for the general manager and marketing coordinator. |
Mixing salaried staff with assembly labor and understating contribution margin. |
| Assembly Labor |
Variable |
Charge per unit produced, such as $4.00 for house assembly or $0.50 for tube cutting. |
Treating labor as fixed when output growth requires more paid production time. |
| Packaging |
Variable |
Charge per unit shipped, including boxes, sleeves, envelopes, bags, and display packaging. |
Putting packaging in overhead even though it rises with every sale. |
| Payment Processing Fees |
Variable |
Apply to revenue, starting at 2.9% in the first year. |
Leaving card fees below the break-even line and overstating gross profit. |
| Factory Utilities |
Semi-variable |
Model the 0.5% revenue-linked charge separately from base utilities and internet. |
Counting all utilities as fixed even when production use rises. |
| Equipment Calibration |
Semi-fixed |
Use step changes as equipment use and production scale increase. |
Treating calibration as a per-order fee instead of a capacity-driven expense. |