Bundle Deals checkout math doesn't add up

Anyone in Europe notice the "estimated import charges" on Bundle Deals checkout? I tested it two times with totally different items and found it confusing. Sharing here because I think this needs more eyes on it.

I saw someone else asking how AliExpress groups items and calculates customs duty. This is different: I want to break down two specific numbers on the checkout page, and check if they actually match the EU's flat 3€ per HS code rule for packages under 150€.

You can't mix categories in one bundle

Before getting into the math, here's something odd I noticed first. The Bundle Deals page splits everything into five tabs. I tried adding items from two different tabs to build one bundle. It doesn't work. Each tab keeps its own separate "My picks" list, and you checkout one tab at a time.

Why it does not allow me to checkout?

Two test carts:

Test 1: 3 cheap items, items total 10.00€, subtotal after discount 4.57€; looks like the cheap AliExpress is back

First cart

first checkout

Test 2: 3 items above 3€ each from Textiles, items total 30.34€, subtotal after discount 14.57€

Two completely different carts, different category, different item prices. But the estimated import charges and the duty reduction are the exact same number.

Second Cart

Second Checkout

Why this looks off?

If the €3 per category rule were applied correctly, the estimated charge should come from real customs classification, but where can I see the actual customs category of an item?

8.97 divided by 3 items equals 2.99€ per item. That makes me think AliExpress calculates this as if every item triggers its own separate duty first, before any bundle logic kicks in, instead of starting from the correct one-category-one-duty baseline the EU rule actually sets.

On the discount side, "Buy 3+, duty covered" removes exactly 3.00€, matching the bundle benefit they advertise. But there's a second line, "Duty benefits -5.97€," that covers whatever is left. 3.00 + 5.97 = 8.97. The two discount lines always add up to cancel the estimated charge completely, no matter what's in the cart.

What I'm trying to figure out:

1. Is "Estimated import charges" actually calculated from real customs categories, or is it just a placeholder number that shows up the same way inside Bundle Deals regardless of what you pick

2. What exactly is "Duty benefits"? Is AliExpress covering the difference themselves as some kind of promotion, or is this a separate discount unrelated to the actual duty

Since both numbers landed on exactly 8.97€ and -8.97€ in two unrelated tests, is that a coincidence tied to these specific categories, or does Bundle Deals always cancel the import charge fully no matter what you buy

If anyone has tested Bundle Deals with a different item count, category, or higher value items, I want to know if you get the same 8.97/duty benefits pattern or something different.

If you can, type out the exact numbers from your Order Summary page (items total, subtotal, estimated import charges, duty reduction breakdown). Would help a lot to compare if it is actually saving