Amazon FBA Online Arbitrage – Case Study: 21% ROI

This case study shows how to find a profitable product online and sell it on Amazon using FBA – a process called Amazon online arbitrage. We will look at a product bought online in the EU and sold on the Amazon.co.uk marketplace with FBA. The same method works on every Amazon marketplace, although sale prices can vary a lot between them.

Key numbers
Product	LEGO City 60345 Farmers Market Van (retired set)
Bought from	BrickLink store in Belgium, €29.44 per set
Sold on	Amazon.co.uk via FBA
Sales (BSR history)	about 5–10 units per month, stable for 3 months
Competition	4–9 offers; 4 sellers at the time of analysis
Target sale price	£48.93
Total cost incl. shipping and duty	€33.64 incl. VAT
Profit	€7.10 per unit
ROI	21%

How to find profitable products to sell on Amazon

Finding profitable products is not easy and it takes time. There are many paid online tools that can help, but you still have to go through many online stores and check products one by one – and the competition is big.

From my experience, a good strategy is to look for discontinued products that are no longer being produced. Amazon usually stops selling these, the number of other sellers decreases over time, and the selling price can go up. That is exactly what we are looking for.

In this study we focus on Lego. Lego sets typically stay on the market for 2–3 years, sometimes longer depending on the theme. The best time to sell them on Amazon is just after they are retired. You can check directly on Lego.com whether a set is retired.

Note: you need approval from Amazon to sell Lego.

Finding a profitable Lego set

Finding a profitable set for online arbitrage takes some effort. You need to go through online stores and check, set by set, whether they are retired. I found set 60345 on BrickLink in the store NickThaBrick, which is located in Belgium and had 105 sets in stock for €29.44 each.

Once you know the set is retired, go to Amazon and search for the set number – in our case Lego 60345. Listings are sometimes duplicated, so open the first one.

Analyzing the Amazon listing

Now we need to check whether the set is selling, at what price, and how many sellers are on the listing. Based on this data we will calculate whether the product is profitable. All of the following data comes from the ProductPanel Chrome extension.

1. Best Sellers Rank, offers and price history

The first thing I look at is the BSR history. The BSR chart shows how well the product sells: each drop in the chart represents a sale.

The chart shows the set has been selling around 5–10 units a month over the last 3 months, and sales are stable, which looks good. The number of offers also looks good – it moves between 4 and 9 sellers, which is very low.

When a set is retired, Amazon is unlikely to sell it again, but it is worth checking. The last time Amazon sold this item was on 15 July 2023. The Buy Box price has been around £42 over the last 3 months.

2. Competitor check

Now it is time to check the competitors – the live offers on the listing. We want to see every seller offering the product, their rating, stock count and fulfillment method (FBA or FBM).

There are only 4 sellers, and the Buy Box seller has only 1 unit in stock. They will most likely sell out soon and the lowest price will jump to £48.93 – the price we can sell the product for.

3. Calculating profit and ROI

Everything looks good so far, so we can calculate whether the product is profitable. The set costs €29.44. We need to add shipping and – only in this case, because the set ships from the EU to the UK – import duty:

• Shipping from the BrickLink store to me and then to the UK: €3.00 per set
• Import duty on Lego (4%): €1.20
• Total cost: 29.44 + 3.00 + 1.20 = €33.64 including VAT

When calculating profit you have to consider your tax status and residence, where you buy products and which marketplace you sell on. The calculation would be quite different for a US seller buying in the US and selling on Amazon.com. In this case we have to include VAT.

At a sale price of £48.93, Amazon’s fees are a £7.49 referral fee and a £3.37 FBA fee, the sale includes £8.16 VAT, and £5.00 of VAT paid on the costs can be deducted. The final profit is €7.10 per set with a 21% ROI, which is a good result for Amazon online arbitrage. Before you buy, also plan how long the stock will sit in Amazon’s warehouse with the FBA storage fee calculator – especially if the units will be stored during the October–December peak.

Conclusion

This case study showed a real example of finding a profitable product for Amazon online arbitrage. Because many sellers buy and sell internationally, I used a product bought in Belgium and sold in the United Kingdom.

Online arbitrage can still be a profitable way to make money on Amazon. My advice is to pick a product category, learn its specifics and stick with it – as with Lego in this example. That makes sourcing more efficient and saves a lot of time.