1. Unbalanced supply and demand: With the development of economy and people's pursuit of tourism, the demand for hotels has greatly increased, while the supply of budget hotels is relatively insufficient, resulting in an imbalance between supply and demand. In the case of short supply, hotels usually raise prices.

2. Resource optimization: In order to meet the market demand, some hotels that were originally positioned as budget hotels began to upgrade their hardware facilities and service levels, which increased the hotel's comfort and experience, but also brought about an increase in costs. In order to make up for the increase in costs, hotels have to raise prices.

3. Brand premium: Some budget hotels have successfully created their own brand premium by improving decoration, improving service quality and creating a unique brand image. These hotels can usually attract more high-end customers who are willing to pay higher prices for the value and experience represented by the brand.

4. External factors: In addition to the improvement of supply and demand and resources, external factors will also have an impact on the price of budget hotels. For example, in places with good geographical location and strong demand around tourist attractions, and in certain seasons or holidays, hotel prices usually rise.

To sum up, the booking volume of popular hotels in China has soared, which leads to the price increase of budget hotels due to the imbalance between supply and demand, resource optimization, brand premium and external factors. As consumers, we can plan ahead when booking hotels, and choose off-season or off-season booking to get more affordable prices. In addition, you can also pay attention to some emerging hotel booking platforms, or choose other types of accommodation, such as B&B and Youth Travel Service, to find more economical accommodation options.