1. Platform differences: Taobao and PDD are different e-commerce platforms, with different operating costs, positioning and user groups, which may lead to different commodity prices on the platforms.

2. Channel cost: Different purchase channels and sales strategies may lead to price differences. For example, some sellers may obtain products through official channels, and some sellers may obtain products through third-party channels. The costs of these two channels may be different.

3. Promotional activities: Different promotional activities and discounts may lead to price differences. For example, some sellers may attract customers through price reduction or special promotion.

4. Brand effect: The effect of different brands may also lead to price differences. For example, some brands may charge higher prices because of their brand influence or popularity.

In a word, the price difference may be caused by many factors. When purchasing, consumers should choose the appropriate purchasing channels and products according to their own needs and budgets.