Value the bundle as a buyer first
Start with the lowest realistic price you would pay for the exact tool, batteries, charger and accessories—not the combined list prices. If you need the complete kit, the bundle discount may be valuable even when individual components are common.
Do not call every extra item free
A battery or tool is only economically free when the rest of the bundle already justifies the entire purchase price for you. Otherwise, the cost is spread across every component, even if the receipt or promotion assigns an artificial line-item value.
Use sold prices, not hopeful listings
Active marketplace listings show what sellers want. Completed sales show what buyers have recently paid. Match capacity, model, condition and included packaging, then subtract platform fees, shipping, supplies and a reasonable allowance for returns.
Account for market saturation
A heavily promoted bundle can release hundreds of identical batteries and tools into the resale market at once. Even useful products may sell slowly or require lower prices when many sellers are competing for the same buyers.
Keep the complete kit when it solves the need
Breaking up a bundle adds work and can make the remaining piece harder to sell. If a typical buyer would logically choose the discounted kit over one component, the intact bundle may have more practical value than the sum of optimistic resale estimates.