How to price a BOM across Digi-Key, Mouser and other distributors

1. Start from exact manufacturer part numbers

Every distributor has its own SKU, but the manufacturer part number (MPN) is the key that lets you compare them. Search by the full MPN including suffixes. The suffix is often the difference between a reel and a tube, between two temperature grades, or between lead and lead-free finish, and each of those can be priced differently and stocked differently.

Distributor keyword search is forgiving, which is the problem: a search for one MPN can return a sibling part first because it is in stock and the exact one is not. Circuit Sherpa normalises the MPN in each result and marks the ones that match what you typed exactly, so a substitute never gets priced as if it were your part.

2. Read the price break for your quantity, not the headline price

Distributors publish a ladder of price breaks: a price at 1, at 10, at 100, at 1,000 and so on. The number displayed in search results is almost always the quantity-1 price. For a 250-piece build the applicable tier is the largest break quantity that does not exceed 250, and the unit price there is often a fraction of the headline figure. Two distributors can rank in opposite order at quantity 1 and at quantity 250.

The line cost you want is: applicable tier unit price multiplied by your quantity. Do that per line, per distributor, and only then compare.

3. Check minimum order quantity and stock at that quantity

Some offers have a minimum order quantity (MOQ) above 1, and reel-only offers can have an MOQ in the thousands. A line for 5 pieces against an offer with an MOQ of 2,500 is not orderable at the price you see. Stock matters the same way: an offer with 40 in stock cannot fill a 250-piece line, no matter its price.

When you do this by hand, write the MOQ next to every line that has one. When Circuit Sherpa prices a BOM it keeps the tier it used and adds a warning to any line whose quantity is below the offer's MOQ, stating the tier that was priced and the quantity the actual order would have to be.

4. Doing it by hand across Digi-Key, Mouser and LCSC

1. Put your BOM in a spreadsheet with one row per line: MPN, quantity, and a column per distributor.
2. For each MPN, open Digi-Key and Mouser, search the exact MPN, and copy the unit price at the tier that covers your quantity plus any MOQ and the stock figure.
3. Do the same on LCSC, which is often the low-cost source for passives and Chinese-manufactured parts and is the native catalogue if the board is going to JLCPCB for assembly. Note that LCSC lists prices in the currency you select and that its stock is held in China, so lead time and import handling differ.
4. Multiply tier price by quantity for each cell, then take the minimum per line for the lower-bound cost.
5. Count how many distributors that lower bound needs. Try consolidating to one or two and see what the total rises to; that difference is what the extra shipping and purchase orders have to justify.
6. Save the spreadsheet with the date. You will want it next build to see what moved.

For a 20-line BOM this is an hour of careful work. For a 300-line BOM it is a day, and it goes stale as soon as it is finished.

5. What Circuit Sherpa automates, and what it does not

What it does, on the Pro and Team plans:

• Accepts a CSV with a part-number column (mpn, part number, part_number, partnumber or part) and an optional qty or quantity column. Up to 500 lines and 2 MB per upload.
• For each line, searches Digi-Key and Mouser live through their APIs, plus the Nexar network when configured, prefers an exact MPN match, and picks the best offer at your quantity using each offer's price-break ladder.
• Computes line cost as tier unit price times quantity, records the tier used, and flags lines below MOQ with the quantity an actual order would need.
• Sums the found lines, lists the lines it could not find so you can handle them by hand, and keeps the upload for 90 days so the next run can be compared against it.
• Lets you set a price alert on the lines that dominate cost, checked daily.

What it does not do, so you are not surprised:

• It does not query LCSC, or any distributor outside Digi-Key, Mouser and the Nexar feed, directly. If LCSC is a candidate supplier for your board, check those lines on LCSC yourself.
• It does not place orders or hold inventory. Buy links go to the distributor.
• It does not accept Excel files yet; export to CSV first.
• It does not apply your negotiated pricing or distributor account discounts; figures are the public price breaks.

6. Deciding whether the tool is worth it

The free plan gives 10 single-part searches a day, which is enough to check whether the live prices are what you expect. BOM upload is on Pro at $29 a month. The honest test is the hand method above: if you re-price a BOM more than about once a month, the time saved covers the subscription; if you price one BOM a year, the spreadsheet is fine and Octopart or Findchips will give you wider distributor coverage for free. See how Circuit Sherpa compares with Octopart and Findchips, or read how price alerts work between builds.