How to Calculate ROI on LEGO Sets (With Real Examples)

Category: investing

By BrickBucks Team

8 min read

Most LEGO investors dramatically overestimate their returns. Learn the complete ROI formula including platform fees, shipping, storage, and taxes — with a worked example showing why "90% profit" is really 3.9%.

Why ROI Matters More Than Raw Profit

A LEGO set that earns you $50 profit sounds great — until you realize you had $400 tied up for three years to make it. Meanwhile, a $20 profit on a $50 set over the same period absolutely crushed it. The difference? Return on Investment, or ROI — the single most important metric for evaluating whether a LEGO investment was actually good.

ROI tells you how efficiently your money worked. It's the number that lets you compare a LEGO Millennium Falcon against a Botanicals set, or even compare LEGO investing against putting that money in an index fund. Without it, you're guessing.

The Basic ROI Formula

At its simplest, ROI is:

ROI = ((Selling Price − Total Cost) / Total Cost) × 100

If you bought a set for $100 and sold it for $150, your ROI is ((150 − 100) / 100) × 100 = 50%. Simple enough. But the devil is in the details — and most LEGO investors dramatically overestimate their returns by ignoring real costs.

The Real Costs Most Investors Forget

Your "total cost" is not just the sticker price. Here's what a complete cost picture looks like:

1. Purchase Price (After Discounts and Taxes)

Start with what you actually paid — including sales tax. If you bought a $199.99 set at 20% off with 8% sales tax, your real purchase price is $172.79, not $160. Tax is real money, and it adds up across a portfolio.

2. Selling Platform Fees

Where you sell matters enormously:

On a $300 sale via eBay, you're losing roughly $40-45 to fees. That's not trivial — it can turn a profitable investment into a mediocre one.

3. Shipping Costs

LEGO boxes are large and heavy. Shipping a Creator Expert modular building can easily cost $15-25 domestically, more internationally. If you offer "free shipping" to attract buyers, that cost comes directly from your profit.

4. Packaging Materials

Proper shipping means oversized boxes, bubble wrap, and tape. Budget roughly $3-5 per shipment for materials if you're shipping regularly.

5. Storage Costs

This one gets overlooked constantly. If you're renting storage space — or even if you're using part of your home — there's a real cost. A 5×10 storage unit runs $75-150/month depending on location. Even if you use your spare bedroom, that space has opportunity cost.

For a rough estimate: divide your annual storage cost by the number of sets stored. If you're paying $100/month for storage holding 200 sets, each set costs $6/month in storage — $72/year per set.

Worked Example: LEGO Icons Boutique Hotel 10297

Let's walk through a real example with actual numbers.

Now let's say you sold it for $380 on eBay 18 months after retirement:

True ROI = ((306.70 − 295.19) / 295.19) × 100 = 3.9%

Compare that to the naive calculation: ((380 − 200) / 200) × 100 = 90%. The real ROI is 3.9%, not 90%. That's the difference between feeling rich and knowing your actual returns.

Annualized ROI: The Missing Piece

A 50% ROI over one year is spectacular. A 50% ROI over five years is just 8.4% annualized — decent but not earth-shattering. To properly compare investments held for different periods, you need annualized ROI:

Annualized ROI = ((1 + ROI/100) ^ (1/years) − 1) × 100

This is the number that lets you compare a set you held for 6 months against one you held for 3 years, and against the S&P 500's historical ~10% annual return.

When ROI Math Says "Don't Buy"

ROI analysis isn't just for measuring wins — it's even more valuable for avoiding bad investments. Before buying a set, run the numbers backwards:

1. Estimate the likely aftermarket price 1-2 years after retirement
2. Subtract platform fees (13-15% for eBay), shipping ($15-25), and packaging ($4)
3. Add storage costs for the holding period
4. Calculate the expected true ROI
5. Compare against your minimum acceptable return (many LEGO investors target 15%+ annualized)

If the math doesn't work at the current price, wait for a sale. A 20% discount on a $200 set ($40 saved) directly translates to a dramatically higher ROI — often turning a marginal investment into a strong one.

Track Your Portfolio Like a Real Investor

The most successful LEGO investors track every purchase with full cost basis from day one. For each set, record:

• Purchase price (actual amount paid, after discounts)
• Sales tax paid
• Purchase date (for holding period calculations)
• Storage allocation (monthly cost per set)
• Condition notes (sealed, opened, damaged box — affects sale price)

When you sell, record the sale price, all fees, shipping cost, and sale date. Your true ROI will be waiting for you — no guesswork needed.

The BrickBucks set database provides current market valuations and historical price data to help you estimate realistic aftermarket prices before you buy — so you can run these ROI calculations before committing your capital, not after.

Key Takeaways

• Always calculate ROI using total cost (purchase + tax + storage) and net proceeds (sale price minus all fees and shipping)
• Use annualized ROI to compare investments held for different periods
• Platform fees alone (13-15% on eBay) can cut your apparent profit in half
• Storage costs are the silent portfolio killer — track them per set
• Run the ROI math before buying to avoid investments that look good but aren't