Sourcing calculator: check a deal will actually make money before you buy

Preview profit, margin and ROI on a potential deal by entering buy cost, sell price, postage, fees and ad rate before you commit.

The sourcing calculator lets you test a potential deal before you spend any money on it. Enter what you would pay, what you think it will sell for, and DashVue previews the profit, margin and ROI you could expect, using your own VAT status so the numbers reflect how your business is actually taxed.

Where to find it

The sourcing calculator sits on its own page, separate from your live listings and stock. It is meant for “what if” checks: stock you are considering buying, a car boot or wholesale lot you have spotted, or a listing idea you want to sanity check before committing cash. Nothing you enter here affects your actual inventory or listings until you decide to act on it.

What you enter

To preview a deal, fill in the fields for the item you are considering:

  1. Buy cost: what you would pay to source the item.
  2. Sell price: what you expect to list and sell it for.
  3. Postage: what you expect to pay to ship it, or charge the buyer.
  4. Fees: the eBay and payment fees you expect on the sale.
  5. Ad rate: the promoted listings ad rate you expect to pay, if any.

As you fill these in, the calculator previews the profit, margin and ROI (return on investment) you would make on the deal, so you can see straight away whether it is worth pursuing.

DashVueAsk DashVueAIOVERVIEWShipDashboardCalendarSTOCKStockRepricerSELLINGOrdersOffers3ReturnsMessagesFeedbackFINANCEReportsTax centreExpensesCost of GoodsInsightsSettingsSAccountseller@example.comBUY DECISIONSourcing calculatorBefore you spend a penny on stock, check it'll actually make money after eBay's cut and the taxman's.The dealEnter what you'd pay and what you'd sell for. Everything updates live.You'll pay£10.00Sell for£30.00Postage cost£3.00Other costs£0.50eBay fee12.9%Ad rate0%Quantity1VAT registeredStandardFlat RateMarginYou'll pay VAT only on your profit margin,not the full sale price.Prefilled from your business profileThis is a strong buyStrong buyHealthy margin and return, worth sourcing with confidence.PROFIT PER UNIT£9.30PROFIT / UNIT£9.30after every costMARGIN31%of the sale priceROI69%return on cash outBREAKEVEN£16.80lowest safe priceWhere each sale goesHow your sale price splits between costs, fees, tax and the profit you keep.You pay £10.00Postage £3.00Other £0.50eBay fees £3.87VAT £3.33Profit £9.30Price safetyBreakeven £16.80Your price £30.00The numbersSale price£30.00You pay-£10.00Postage-£3.00Other costs-£0.50eBay fees-£3.87VAT to pay-£3.33Profit per unit£9.30An estimate to guide a buying decision. eBay fees vary by category and shop tier, and the VAT figure assumes yourscheme as set. Confirm the exact final value fee for the category before committing to volume.
The full Sourcing calculator page with the deal inputs highlighted: enter what you'll pay, sell for, postage, fees and ad rate on the left, and DashVue previews the verdict, profit, margin, ROI and breakeven, plus a cost breakdown and line-by-line numbers, on the right.

VAT status and scheme

Your VAT status and scheme, standard, flat rate, or margin scheme, are prefilled from your business profile, so the preview reflects how VAT actually applies to your business rather than a generic assumption. This matters because the same buy cost and sell price can produce a different profit figure depending on which scheme you are on, particularly under the margin scheme, where VAT is due on the margin rather than the full sale price.

If your VAT status or scheme changes, update it in your business profile so future previews stay accurate.

A preview, not a booking

The sourcing calculator is a standalone preview tool. Entering figures here does not create a listing, add stock, or record a cost against any item. If you go ahead with the deal, you still need to add the stock and set its cost separately so it is reflected in your actual profit tracking.

See the related articles below for more on tracking item costs and profit.

Last updated 2026-07-06.

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