When buying a G-spot or P-spot dildo, there are a few things to keep in mind:

1. Choose a reputable seller: Look for a seller with a good reputation and a track record of selling high-quality sex toys. In addition, it is vital to ensure you're buying from a seller who prioritizes your safety and privacy.
2. Check the materials: Make sure the dildo is made from body-safe materials, such as medical-grade silicone, glass, or metal. Avoid dildos made from porous materials, which can harbor bacteria and be difficult to clean.
3. Consider the size and shape: Choose a dildo that is comfortable and effective for your body. Consider the size, shape, and curve of the dildo to ensure that it will be comfortable and provide the desired stimulation level.
4. Look for added features: Some G-spot and P-spot dildos may have added features like texture or vibrations. Consider whether these features are essential to you when choosing a dildo.
5. Read reviews: Look for reviews from other users to understand the dildo's effectiveness and overall quality. This can be a helpful way to gauge whether or not the dildo will be a good fit for you.
6. Discreet packaging: Ensure the seller offers discreet packaging to protect your privacy and prevent anyone from knowing what is inside the package.

By considering these factors, you can find a high-quality G-spot or P-spot dildo that is comfortable, effective, and enjoyable to use.