Before I ordered my first product from Alibaba, I made a classic beginner mistake. I saw a unit price of $1.70 and immediately started calculating profit in my head. I was already thinking about how many units I could sell.

That number meant almost nothing.

Here is how I actually think about it now, using my charger order as a real example.
Start with the landed cost, not the unit price
The landed cost is what you actually pay per unit by the time the product is in your hands. It includes everything: product cost, shipping, duties, and taxes.
With my chargers, the math looked like this.
I ordered 50 units at $1.70 each. Total product cost came to around $104. Then came shipping, which was $65. On top of that, VAT added another $15. So total shipping costs were $80.
$104 + $80 = $184 for 50 units.
That puts the real cost at about $3.70 per charger, not $1.70.

Before you place any order, do this calculation. MOQ multiplied by unit price, plus a realistic shipping estimate, plus roughly 20-25% for taxes and duties depending on your country. Divide by the number of units. That number is your baseline.
Then check what the market is actually paying
Once you know your landed cost, look at what the same or similar product sells for. Not the retail price in a supermarket. The price someone is actually paying on eBay, Amazon, Vinted, or wherever you plan to sell.
When I checked, chargers like mine were going for between $19 and $25 in stores. On resale platforms, people were moving them for around $12 to $15.
I set my price at $13 per unit.

The margin calculation
Selling price minus landed cost gives you gross margin per unit.
$13 minus $3.70 equals roughly $9.30. That sounds fine until you factor in your time to list, package, and ship each unit. For 50 units it was manageable. For 500, you need to think harder about whether that margin justifies the work.
A rough rule I use: if the selling price is not at least double the landed cost, the product is risky. Markets shift, competition appears, and you need room to discount without losing money.
With the chargers I was just above that threshold. Not a great product, but not a disaster either.
Where most people go wrong
The product price on Alibaba is almost always the most attractive number on the page. Shipping, especially for small orders, can easily add 50 to 80 percent on top of what you paid for the goods. I had no idea until I received the shipping quote.
That is why I now calculate shipping before I even decide if a product interests me. If the product is heavy, bulky, or low in value relative to its weight, the numbers often stop working before you even start.
The charger order taught me more than any article could have. I made money, but not as much as I thought I would when I first saw that $1.70 figure. Next time I will know where to look first.