Choosing a cost-effective digital camera suitable for the student party needs to consider the following factors: price, performance, simplicity of operation and portability. The following are some recommended models, and these cameras perform well in cost performance:

1. canon) PowerShot G7 X Mark III: This camera has a compact body and excellent shooting performance, which is suitable for students who like taking photos and videos.

2. Sony RX 100VII: This camera has professional performance and miniaturization design, which is suitable for students who have high requirements for image quality.

3. Nikon) Coolpix A: This camera has a stylish appearance and good shooting performance, which is suitable for students who want to take pictures easily.

4. fujifilm X-A7: This camera has a retro appearance and excellent shooting performance, which is suitable for students who like photography.

5. Ricoh) GR III: This camera is simple in design and powerful in taking pictures, which is suitable for students who like high-quality shooting.

Please note that the performance of digital cameras will be constantly updated over time, so please pay attention to the latest product information when purchasing. In addition, when choosing a camera, please decide which camera to buy according to your own needs, budget and shooting preferences.