Alibaba is a large e-commerce platform with many products to choose from. Generally speaking, the following categories of goods are more cost-effective to buy on Alibaba:

1. Clothing and accessories: There are a large number of clothing and accessories suppliers on Alibaba, and the prices are usually cheaper than other platforms.

2. Household items: These products are often large in size, so it is more cost-effective to buy them on Alibaba.

3. Electronic products: Since electronic products are updated quickly and the prices are relatively high, you may find some products with more reasonable prices on Alibaba.

4. Office supplies: There are many office supply suppliers on Alibaba, and the prices are usually cheaper than in physical stores.

5. Outdoor products: For camping, hiking, fishing and other supplies, you may find some good price options on Alibaba.

6. Crafts and toys: There are a large number of crafts and toys suppliers on Alibaba, and the prices are often cheaper than other platforms.

In short, shopping on Alibaba requires careful selection of reliable suppliers and careful comparison of prices and quality. At the same time, also pay attention to the product's shipping and return and exchange policies.