To buy and sell logos online, you can follow these general steps:

### Buying Logos:

1. **Browse Logo Marketplaces:**
Explore online marketplaces dedicated to selling logos, such as GraphicRiver, LogoGround, or BrandCrowd.

2. **Filter and Search:**
Use filters and search functions to narrow down options based on your preferences, industry, or style.

3. **Preview and Purchase:**
Preview logos, check for customization options, and once satisfied, follow the platform’s purchasing process to buy the logo.

### Selling Logos:

1. **Create a Portfolio:**
Build a portfolio showcasing your logo design skills. Include a variety of styles to attract a broader audience.

2. **Join Logo Marketplaces:**
Register on logo marketplaces like those mentioned earlier and follow their guidelines for submitting and selling logos.

3. **Set Pricing:**
Determine reasonable pricing for your logos. Consider factors like complexity, exclusivity, and rights granted to the buyer.

4. **Upload Your Logos:**
Upload your logos to the marketplace, providing accurate descriptions and tags for better visibility.

5. **Handle Transactions:**
Most platforms handle transactions, but be aware of any fees associated with sales. Ensure a smooth delivery process for the purchased logos.

6. **Build Your Brand:**
Develop a personal brand as a logo designer. Utilize social media and your own website to showcase your work and attract potential clients.

Remember to review the terms and conditions of each platform to understand their policies on pricing, exclusivity, and rights.