Skip to main content
A lot contains cards with recent sold results totaling $1,000. What is the most you can pay? The answer is not $1,000 minus a favorite percentage. The comp total is only a reference. Your maximum offer depends on what this lot is likely to produce after accounting for condition, selling costs, required work, uncertainty, and the contribution the business requires. Once a purchase is made, its price is fixed. Build the ceiling before the negotiation makes you want the deal.

Start with realizable value

Recent sold results are a better starting point than active asking prices, but only when the sales are genuinely comparable. Match the exact item and printing, similar condition, a venue you could realistically use, and a date close enough to reflect the current decision. Then move from comp total to expected realizable value: the gross sale proceeds you reasonably expect this specific lot to produce. The two numbers may differ. A mixed collection can include condition uncertainty, lower-demand cards, incomplete items, or products that are unlikely to achieve the strongest individual comp. Write down the adjustment instead of hiding it inside the offer percentage. If $1,000 is the best-supported comp total but $950 is a more realistic sales outcome for this lot, the formula should begin at $950.

Build the ceiling in dollars

Use one equation: Maximum offer = expected realizable value − C_lot − uncertainty reserve − target lot contribution Each deduction has a different job:
  • C_lot is the whole lot’s modeled selling and fulfillment cost: verified outlays, explicit loss allowance, labor, and allocated operating costs required to complete its expected sales.
  • Uncertainty reserve protects against forecast errors that are not already reflected in realizable value or costs.
  • Target lot contribution is the minimum modeled contribution the lot must leave after the other allowances. State it in dollars so it cannot disappear inside an undefined percentage. It is a purchase-model boundary, not net profit.
Here is one teaching model. Every amount is invented and rounded for the calculation; none is a current fee or market benchmark.
InputAmountRole in the model
Recent sold comp total$1,000Reference, not the offer
Expected realizable value$950$1,000 comps less a $50 known condition/mix adjustment
Whole-lot modeled cost, C_lot−$130Placeholder: $80 of other modeled costs plus five labor hours at an invented $10 internal rate
Uncertainty reserve−$20Forecast error not counted elsewhere
Target lot contribution−$100Reader-chosen required contribution in this example
Maximum acquisition offer$700$950 − $130 − $20 − $100
The $700 ceiling happens to equal 70% of the $1,000 comp total. That does not make 70% the rule. It is simply the result of these assumptions. If other modeled costs rise by $40 while every other input stays fixed, the total modeled cost becomes $170 and the ceiling falls to $660.

Change the input that actually changed

Do not compensate for every concern by choosing a lower percentage. Name the source of the difference. A clean, accurately itemized lot may require less research and sorting, reducing the labor inside modeled cost. Condition problems can lower expected realizable value or require more uncertainty reserve. Thin demand can reduce the realistic sale outcome or make the lot a pass. Repeated handling, many low-value listings, or difficult identification can raise labor enough to erase an otherwise attractive purchase-to-sale price gap. Be careful not to count the same risk twice. If likely condition discounts already reduce expected realizable value, do not automatically deduct the full amount again as uncertainty. Known fees, owner work, and an explicit historical or scenario-based loss allowance belong in modeled cost. Residual forecast error that is not already counted belongs in the reserve. The maximum offer can move up as well. Better information may support the expected sale value, and seller preparation may remove real work. A higher ceiling is justified only when a named input improves—not because the deal feels easier to win.

Calculate one real lot

Complete this before making the offer: Comp set: items ___; condition ___; venue ___; checked on ___ Recent sold comp total: $___ Expected realizable value and reason for adjustment: $___ because ___ Whole-lot modeled cost, C_lot: −$, including other modeled outlays/allocations $, labor $, and loss allowance $ Build this input from the consistently scoped Chapter 2.2 order models the lot is expected to produce, plus any lot-level cost not already allocated. Use the aggregate once rather than subtracting its components again. Uncertainty reserve: −$___ Target lot contribution: −$___ Maximum offer: $___ Planned offer band: $___ to $___ Actual offer: $___ The maximum is a ceiling, not a target. If you plan an offer band, keep its upper edge at or below that ceiling and choose the lower edge from the remaining uncertainty, seller context, and room to negotiate—not from a universal percentage. The actual offer should not exceed the ceiling unless you deliberately change an assumption and can defend the new number. If the seller needs more than the lot can support, the calculation has still done its job: it has shown you where to stop.